diff --git a/app/assets/javascripts/new_design/messagerie.js b/app/assets/javascripts/new_design/messagerie.js
index 1b8d1d324..5f7c67a08 100644
--- a/app/assets/javascripts/new_design/messagerie.js
+++ b/app/assets/javascripts/new_design/messagerie.js
@@ -1,7 +1,23 @@
 TPS.scrollMessagerie = function () {
+  var scrollTo = function ($container, $scrollTo) {
+    $container.scrollTop(
+      $scrollTo.offset().top - $container.offset().top + $container.scrollTop()
+    );
+  }
+
+  var scrollToBottom = function ($container) {
+    $container.scrollTop($container.prop('scrollHeight'));
+  }
+
   var $ul = $(".messagerie ul").first();
   if($ul.length) {
-    $ul.scrollTop($ul.prop('scrollHeight'));
+    var $elementToScroll = $('.date.highlighted').first();
+
+    if ($elementToScroll.length != 0) {
+      scrollTo($ul, $elementToScroll);
+    } else {
+      scrollToBottom($ul);
+    }
   }
 };
 
diff --git a/app/assets/stylesheets/new_design/_colors.scss b/app/assets/stylesheets/new_design/_colors.scss
index c46c85b3d..059b41ef1 100644
--- a/app/assets/stylesheets/new_design/_colors.scss
+++ b/app/assets/stylesheets/new_design/_colors.scss
@@ -12,3 +12,4 @@ $lighter-green: lighten($green, 30%);
 $light-green: lighten($green, 25%);
 $dark-green: darken($green, 20%);
 $orange: #F59415;
+$orange-bg: lighten($orange, 35%);
diff --git a/app/assets/stylesheets/new_design/dossier_champs.scss b/app/assets/stylesheets/new_design/dossier_champs.scss
index 7b663274c..8260c9777 100644
--- a/app/assets/stylesheets/new_design/dossier_champs.scss
+++ b/app/assets/stylesheets/new_design/dossier_champs.scss
@@ -1,6 +1,7 @@
+@import "colors";
 @import "constants";
 
-.dossier-champs {
+.table.dossier-champs {
   th,
   td {
     vertical-align: top;
@@ -9,4 +10,23 @@
   .libelle {
     width: 250px;
   }
+
+  td.updated-at {
+    font-size: 13px;
+    color: $grey;
+    text-align: right;
+    width: 190px;
+
+    > span {
+      opacity: 0;
+
+      &.highlighted {
+        opacity: 1;
+      }
+    }
+  }
+
+  tr:hover .updated-at > span {
+    opacity: 1;
+  }
 }
diff --git a/app/assets/stylesheets/new_design/forms.scss b/app/assets/stylesheets/new_design/forms.scss
index b5f428c2e..41769313d 100644
--- a/app/assets/stylesheets/new_design/forms.scss
+++ b/app/assets/stylesheets/new_design/forms.scss
@@ -7,6 +7,11 @@
     margin-bottom: 20px;
   }
 
+  @mixin notice-text-style {
+    font-size: 14px;
+    color: $grey;
+  }
+
   label {
     margin-bottom: $default-padding;
     display: block;
@@ -16,10 +21,24 @@
     }
 
     .notice {
-      font-size: 14px;
+      @include notice-text-style;
       display: block;
       margin-top: $default-spacer;
-      color: $grey;
+    }
+  }
+
+  .champ {
+    .updated-at {
+      @include notice-text-style;
+      float: right;
+      display: inline-block;
+      margin-left: $default-spacer;
+      visibility: hidden;
+    }
+
+    &:hover .updated-at,
+    .updated-at.highlighted {
+      visibility: visible;
     }
   }
 
diff --git a/app/assets/stylesheets/new_design/utils.scss b/app/assets/stylesheets/new_design/utils.scss
index 599609dd5..44d53176c 100644
--- a/app/assets/stylesheets/new_design/utils.scss
+++ b/app/assets/stylesheets/new_design/utils.scss
@@ -1,3 +1,5 @@
+@import "colors";
+
 .pull-left {
   float: left;
 }
@@ -32,3 +34,8 @@
   text-align: center;
   margin: 60px 0;
 }
+
+.highlighted {
+  background: $orange-bg;
+  color: $black;
+}
diff --git a/app/controllers/new_gestionnaire/dossiers_controller.rb b/app/controllers/new_gestionnaire/dossiers_controller.rb
index 937b07971..6f78b3bff 100644
--- a/app/controllers/new_gestionnaire/dossiers_controller.rb
+++ b/app/controllers/new_gestionnaire/dossiers_controller.rb
@@ -3,29 +3,30 @@ module NewGestionnaire
     include ActionView::Helpers::NumberHelper
     include ActionView::Helpers::TextHelper
 
+    after_action :mark_demande_as_read, only: :show
+    after_action :mark_messagerie_as_read, only: [:messagerie, :create_commentaire]
+    after_action :mark_avis_as_read, only: [:avis, :create_avis]
+    after_action :mark_annotations_privees_as_read, only: [:annotations_privees, :update_annotations]
+
     def attestation
       send_data(dossier.attestation.pdf.read, filename: 'attestation.pdf', type: 'application/pdf')
     end
 
     def show
-      dossier.notifications.demande.mark_as_read
-      current_gestionnaire.mark_tab_as_seen(dossier, :demande)
+      @demande_seen_at = current_gestionnaire.follows.find_by(dossier: dossier)&.demande_seen_at
     end
 
     def messagerie
-      dossier.notifications.messagerie.mark_as_read
-      current_gestionnaire.mark_tab_as_seen(dossier, :messagerie)
       @commentaire = Commentaire.new
+      @messagerie_seen_at = current_gestionnaire.follows.find_by(dossier: dossier)&.messagerie_seen_at
     end
 
     def annotations_privees
-      dossier.notifications.annotations_privees.mark_as_read
-      current_gestionnaire.mark_tab_as_seen(dossier, :annotations_privees)
+      @annotations_privees_seen_at = current_gestionnaire.follows.find_by(dossier: dossier)&.annotations_privees_seen_at
     end
 
     def avis
-      dossier.notifications.avis.mark_as_read
-      current_gestionnaire.mark_tab_as_seen(dossier, :avis)
+      @avis_seen_at = current_gestionnaire.follows.find_by(dossier: dossier)&.avis_seen_at
     end
 
     def personnes_impliquees
@@ -192,5 +193,25 @@ module NewGestionnaire
 
       dossier&.attestation&.emailable?
     end
+
+    def mark_demande_as_read
+      dossier.notifications.demande.mark_as_read
+      current_gestionnaire.mark_tab_as_seen(dossier, :demande)
+    end
+
+    def mark_messagerie_as_read
+      dossier.notifications.messagerie.mark_as_read
+      current_gestionnaire.mark_tab_as_seen(dossier, :messagerie)
+    end
+
+    def mark_avis_as_read
+      dossier.notifications.avis.mark_as_read
+      current_gestionnaire.mark_tab_as_seen(dossier, :avis)
+    end
+
+    def mark_annotations_privees_as_read
+      dossier.notifications.annotations_privees.mark_as_read
+      current_gestionnaire.mark_tab_as_seen(dossier, :annotations_privees)
+    end
   end
 end
diff --git a/app/helpers/dossier_helper.rb b/app/helpers/dossier_helper.rb
index aade09028..3034af966 100644
--- a/app/helpers/dossier_helper.rb
+++ b/app/helpers/dossier_helper.rb
@@ -8,4 +8,10 @@ module DossierHelper
       'refused'
     end
   end
+
+  def highlight_if_unseen_class(seen_at, updated_at)
+    if seen_at&.<(updated_at)
+      "highlighted"
+    end
+  end
 end
diff --git a/app/models/follow.rb b/app/models/follow.rb
index 2df639902..ea18f9e0f 100644
--- a/app/models/follow.rb
+++ b/app/models/follow.rb
@@ -9,9 +9,9 @@ class Follow < ActiveRecord::Base
   private
 
   def set_default_date
-    self.demande_seen_at = DateTime.now
-    self.annotations_privees_seen_at = DateTime.now
-    self.avis_seen_at = DateTime.now
-    self.messagerie_seen_at = DateTime.now
+    self.demande_seen_at ||= DateTime.now
+    self.annotations_privees_seen_at ||= DateTime.now
+    self.avis_seen_at ||= DateTime.now
+    self.messagerie_seen_at ||= DateTime.now
   end
 end
diff --git a/app/views/new_gestionnaire/avis/_avis_list.html.haml b/app/views/new_gestionnaire/avis/_avis_list.html.haml
index 5520cb025..8828f315e 100644
--- a/app/views/new_gestionnaire/avis/_avis_list.html.haml
+++ b/app/views/new_gestionnaire/avis/_avis_list.html.haml
@@ -15,7 +15,8 @@
                 %span.confidentiel
                   confidentiel
                   %span.icon.lock{ title: "Cet avis n'est pas affiché avec les autres experts consultés" }
-              %span.date Demande d'avis envoyée le #{I18n.l(avis.created_at.localtime, format: '%d/%m/%y')}
+              %span.date{ class: highlight_if_unseen_class(avis_seen_at, avis.created_at) }
+                Demande d'avis envoyée le #{I18n.l(avis.created_at.localtime, format: '%d/%m/%y à %H:%M')}
             %p= avis.introduction
 
             .answer.flex.align-start
@@ -24,7 +25,8 @@
                 %h2.gestionnaire
                   = (avis.email_to_display == current_gestionnaire.email) ? 'Vous' : avis.email_to_display
                   - if avis.answer.present?
-                    %span.date Réponse donnée le #{I18n.l(avis.updated_at.localtime, format: '%d/%m/%y')}
+                    %span.date{ class: highlight_if_unseen_class(avis_seen_at, avis.updated_at) }
+                      Réponse donnée le #{I18n.l(avis.updated_at.localtime, format: '%d/%m/%y à %H:%M')}
                   - else
                     %span.waiting En attente de réponse
                 %p= avis.answer
diff --git a/app/views/new_gestionnaire/avis/instruction.html.haml b/app/views/new_gestionnaire/avis/instruction.html.haml
index bd59d91b2..1dc5860d4 100644
--- a/app/views/new_gestionnaire/avis/instruction.html.haml
+++ b/app/views/new_gestionnaire/avis/instruction.html.haml
@@ -42,4 +42,4 @@
           .send-wrapper
             = f.submit 'Demander un avis', class: 'button send'
 
-  = render partial: 'avis_list', locals: { avis: @dossier.avis_for(current_gestionnaire) }
+  = render partial: 'avis_list', locals: { avis: @dossier.avis_for(current_gestionnaire), avis_seen_at: nil }
diff --git a/app/views/new_gestionnaire/avis/messagerie.html.haml b/app/views/new_gestionnaire/avis/messagerie.html.haml
index cf022f20e..d6b71b69b 100644
--- a/app/views/new_gestionnaire/avis/messagerie.html.haml
+++ b/app/views/new_gestionnaire/avis/messagerie.html.haml
@@ -6,6 +6,6 @@
   %ul.messages-list
     - @dossier.commentaires.each do |commentaire|
       %li
-        = render partial: "new_gestionnaire/shared/commentaires/commentaire", locals: { commentaire: commentaire }
+        = render partial: "new_gestionnaire/shared/commentaires/commentaire", locals: { commentaire: commentaire, messagerie_seen_at: nil }
 
   = render partial: "new_gestionnaire/shared/commentaires/form", locals: { commentaire: @commentaire, form_url: commentaire_avis_path(@avis) }
diff --git a/app/views/new_gestionnaire/avis/show.html.haml b/app/views/new_gestionnaire/avis/show.html.haml
index cb8994db3..486a2c843 100644
--- a/app/views/new_gestionnaire/avis/show.html.haml
+++ b/app/views/new_gestionnaire/avis/show.html.haml
@@ -16,7 +16,7 @@
     - champs = @dossier.ordered_champs.decorate
     - if champs.any?
       .card
-        = render partial: 'new_gestionnaire/dossiers/champs', locals: { champs: champs }
+        = render partial: 'new_gestionnaire/dossiers/champs', locals: { champs: champs, dossier: @dossier, demande_seen_at: nil }
 
     - if @dossier.procedure.use_api_carto
       .accompagnateur-title Cartographie
@@ -26,4 +26,4 @@
     - if @dossier.procedure.cerfa_flag? || @dossier.types_de_piece_justificative.any?
       .accompagnateur-title Pièces jointes
       .card
-        = render partial: "new_gestionnaire/dossiers/pieces_jointes", locals: { dossier: @dossier }
+        = render partial: "new_gestionnaire/dossiers/pieces_jointes", locals: { dossier: @dossier, demande_seen_at: nil }
diff --git a/app/views/new_gestionnaire/dossiers/_champs.html.haml b/app/views/new_gestionnaire/dossiers/_champs.html.haml
index 3abfe424a..1354f4624 100644
--- a/app/views/new_gestionnaire/dossiers/_champs.html.haml
+++ b/app/views/new_gestionnaire/dossiers/_champs.html.haml
@@ -4,7 +4,7 @@
       %tr
         - case c.type_champ
         - when "header_section"
-          %th.header-section{ colspan: 2 }
+          %th.header-section{ colspan: 3 }
             = c.libelle
         - when "multiple_drop_down_list"
           %th.libelle
@@ -34,4 +34,10 @@
           %th.libelle
             = "#{c.libelle} :"
           %td.rich-text
-            = sanitize(c.value)
+            %span{ class: highlight_if_unseen_class(demande_seen_at, c.updated_at) }
+              = sanitize(c.value)
+        - if c.type_champ != "header_section"
+          %td.updated-at
+            %span{ class: highlight_if_unseen_class(demande_seen_at, c.updated_at) }
+              modifié le
+              = c.updated_at.localtime.strftime("%d/%m/%Y à %H:%M")
diff --git a/app/views/new_gestionnaire/dossiers/_pieces_jointes.html.haml b/app/views/new_gestionnaire/dossiers/_pieces_jointes.html.haml
index c37a65765..7618de5bc 100644
--- a/app/views/new_gestionnaire/dossiers/_pieces_jointes.html.haml
+++ b/app/views/new_gestionnaire/dossiers/_pieces_jointes.html.haml
@@ -1,4 +1,4 @@
-%table.table.vertical.pj
+%table.table.vertical.pj.dossier-champs
   %tbody
     - if dossier.procedure.cerfa_flag?
       %tr
@@ -8,17 +8,22 @@
             = link_to "Télécharger", @dossier.cerfa.last.content_url, class: "link", target: :blank
           - else
             Pièce non fournie
+        %td
+
 
     - dossier.procedure.types_de_piece_justificative.each do |type_de_piece_justificative|
+      - pjs = dossier.retrieve_all_piece_justificative_by_type(type_de_piece_justificative.id).to_ary.dup
+      - pj = pjs.shift if pjs.present?
       %tr
         %th= "#{type_de_piece_justificative.libelle} :"
-        - pjs = dossier.retrieve_all_piece_justificative_by_type(type_de_piece_justificative.id).to_ary.dup
-        - if pjs.present?
-          - first_pj = pjs.pop
-          %td= display_pj_filename(first_pj)
-          %td= link_to "Télécharger", first_pj.content_url, class: "link", target: :blank
+        - if pj
           %td
+            %span{ class: highlight_if_unseen_class(demande_seen_at, pj.updated_at) }
+              = display_pj_filename(pj)
+            ·
+            = link_to "Télécharger", pj.content_url, class: "link", target: :blank
             - if pjs.present?
+              %br
               %span.button.dropdown
                 anciennes versions
                 .dropdown-content.fade-in-down
@@ -28,6 +33,11 @@
                         = link_to pj.content_url, { target: :blank } do
                           %span.filename= display_pj_filename(pj)
                           %span
-                            ajoutée le #{pj.created_at.localtime.strftime('%d/%m %H:%M')}
+                            ajoutée le #{pj.created_at.localtime.strftime('%d/%m/%Y à %H:%M')}
         - else
           %td Pièce non fournie
+        %td.updated-at
+          - if pj
+            %span{ class: highlight_if_unseen_class(demande_seen_at, pj.updated_at) }
+              modifié le
+              = pj.updated_at.localtime.strftime("%d/%m/%Y à %H:%M")
diff --git a/app/views/new_gestionnaire/dossiers/annotations_privees.html.haml b/app/views/new_gestionnaire/dossiers/annotations_privees.html.haml
index 42193d67f..5fc446f23 100644
--- a/app/views/new_gestionnaire/dossiers/annotations_privees.html.haml
+++ b/app/views/new_gestionnaire/dossiers/annotations_privees.html.haml
@@ -10,8 +10,8 @@
         = form_for @dossier, url: annotations_dossier_path(@dossier.procedure, @dossier), html: { class: 'form' } do |f|
           = f.fields_for :champs_private, f.object.ordered_champs_private do |champ_form|
             - champ = champ_form.object
-            = render partial: "new_gestionnaire/dossiers/champs/#{champ.type_champ}",
-              locals: { champ: champ, form: champ_form }
+            = render partial: "new_gestionnaire/dossiers/champs/champ",
+              locals: { champ: champ, form: champ_form, seen_at: @annotations_privees_seen_at }
 
           .send-wrapper
             = f.submit 'Sauvegarder', class: 'button send', data: { disable_with: "Envoi..." }
diff --git a/app/views/new_gestionnaire/dossiers/avis.html.haml b/app/views/new_gestionnaire/dossiers/avis.html.haml
index 35e446a19..0e9664df0 100644
--- a/app/views/new_gestionnaire/dossiers/avis.html.haml
+++ b/app/views/new_gestionnaire/dossiers/avis.html.haml
@@ -17,4 +17,4 @@
         .send-wrapper
           = f.submit 'Demander un avis', class: 'button send', data: { disable_with: "Envoi..." }
 
-  = render partial: 'new_gestionnaire/avis/avis_list', locals: { avis: @dossier.avis }
+  = render partial: 'new_gestionnaire/avis/avis_list', locals: { avis: @dossier.avis, avis_seen_at: @avis_seen_at }
diff --git a/app/views/new_gestionnaire/dossiers/champs/_address.html.haml b/app/views/new_gestionnaire/dossiers/champs/_address.html.haml
index c0707410f..e4ed08e33 100644
--- a/app/views/new_gestionnaire/dossiers/champs/_address.html.haml
+++ b/app/views/new_gestionnaire/dossiers/champs/_address.html.haml
@@ -1,4 +1,4 @@
-= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ }
+= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ, seen_at: seen_at }
 
 = form.text_field :value,
   'data-address': 'true',
diff --git a/app/views/new_gestionnaire/dossiers/champs/_champ.html.haml b/app/views/new_gestionnaire/dossiers/champs/_champ.html.haml
new file mode 100644
index 000000000..e852d1674
--- /dev/null
+++ b/app/views/new_gestionnaire/dossiers/champs/_champ.html.haml
@@ -0,0 +1,3 @@
+.champ
+  = render partial: "new_gestionnaire/dossiers/champs/#{champ.type_champ}",
+    locals: { champ: champ, form: form, seen_at: seen_at }
diff --git a/app/views/new_gestionnaire/dossiers/champs/_champ_label.html.haml b/app/views/new_gestionnaire/dossiers/champs/_champ_label.html.haml
index 000439a3a..a75334b35 100644
--- a/app/views/new_gestionnaire/dossiers/champs/_champ_label.html.haml
+++ b/app/views/new_gestionnaire/dossiers/champs/_champ_label.html.haml
@@ -2,5 +2,10 @@
   #{champ.libelle}
   - if champ.mandatory
     %span.mandatory *
+
+  - if champ.updated_at.present?
+    %span.updated-at{ class: highlight_if_unseen_class(seen_at, champ.updated_at) }
+      = "modifié le #{champ.updated_at.strftime('%d/%m/%Y à %H:%M')}"
+
   - if champ.description.present?
     %span.notice= champ.description
diff --git a/app/views/new_gestionnaire/dossiers/champs/_checkbox.html.haml b/app/views/new_gestionnaire/dossiers/champs/_checkbox.html.haml
index 2668405ba..882404c2e 100644
--- a/app/views/new_gestionnaire/dossiers/champs/_checkbox.html.haml
+++ b/app/views/new_gestionnaire/dossiers/champs/_checkbox.html.haml
@@ -1,4 +1,4 @@
-= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ }
+= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ, seen_at: seen_at }
 
 = form.check_box :value,
   { required: champ.mandatory },
diff --git a/app/views/new_gestionnaire/dossiers/champs/_civilite.html.haml b/app/views/new_gestionnaire/dossiers/champs/_civilite.html.haml
index b968388f6..456af953e 100644
--- a/app/views/new_gestionnaire/dossiers/champs/_civilite.html.haml
+++ b/app/views/new_gestionnaire/dossiers/champs/_civilite.html.haml
@@ -1,4 +1,4 @@
-= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ }
+= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ, seen_at: seen_at }
 
 .radios
   %label
diff --git a/app/views/new_gestionnaire/dossiers/champs/_date.html.haml b/app/views/new_gestionnaire/dossiers/champs/_date.html.haml
index 5bdd4ad45..86b27120a 100644
--- a/app/views/new_gestionnaire/dossiers/champs/_date.html.haml
+++ b/app/views/new_gestionnaire/dossiers/champs/_date.html.haml
@@ -1,4 +1,4 @@
-= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ }
+= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ, seen_at: seen_at }
 
 = form.date_field :value,
   value: champ.value,
diff --git a/app/views/new_gestionnaire/dossiers/champs/_datetime.html.haml b/app/views/new_gestionnaire/dossiers/champs/_datetime.html.haml
index 4dabb6705..e6a92eceb 100644
--- a/app/views/new_gestionnaire/dossiers/champs/_datetime.html.haml
+++ b/app/views/new_gestionnaire/dossiers/champs/_datetime.html.haml
@@ -1,4 +1,4 @@
-= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ }
+= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ, seen_at: seen_at }
 
 - parsed_value = champ.value.present? ? DateTime.parse(champ.value) : DateTime.now
 
diff --git a/app/views/new_gestionnaire/dossiers/champs/_departements.html.haml b/app/views/new_gestionnaire/dossiers/champs/_departements.html.haml
index c16358e58..bd1bf253d 100644
--- a/app/views/new_gestionnaire/dossiers/champs/_departements.html.haml
+++ b/app/views/new_gestionnaire/dossiers/champs/_departements.html.haml
@@ -1,4 +1,4 @@
-= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ }
+= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ, seen_at: seen_at }
 
 = form.select :value,
   Champ.departements,
diff --git a/app/views/new_gestionnaire/dossiers/champs/_dossier_link.html.haml b/app/views/new_gestionnaire/dossiers/champs/_dossier_link.html.haml
index 54c9d9b12..cbf2dea64 100644
--- a/app/views/new_gestionnaire/dossiers/champs/_dossier_link.html.haml
+++ b/app/views/new_gestionnaire/dossiers/champs/_dossier_link.html.haml
@@ -1,4 +1,4 @@
-= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ }
+= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ, seen_at: seen_at }
 
 - dossier = Dossier.find_by(id: champ.value)
 - show_text_summary = dossier.present?
diff --git a/app/views/new_gestionnaire/dossiers/champs/_drop_down_list.html.haml b/app/views/new_gestionnaire/dossiers/champs/_drop_down_list.html.haml
index ee46b4b26..2f36bceb8 100644
--- a/app/views/new_gestionnaire/dossiers/champs/_drop_down_list.html.haml
+++ b/app/views/new_gestionnaire/dossiers/champs/_drop_down_list.html.haml
@@ -1,4 +1,4 @@
-= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ }
+= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ, seen_at: seen_at }
 
 - if champ.drop_down_list && champ.drop_down_list.options.any?
   = form.select :value,
diff --git a/app/views/new_gestionnaire/dossiers/champs/_email.html.haml b/app/views/new_gestionnaire/dossiers/champs/_email.html.haml
index c9819de88..f065cb6ca 100644
--- a/app/views/new_gestionnaire/dossiers/champs/_email.html.haml
+++ b/app/views/new_gestionnaire/dossiers/champs/_email.html.haml
@@ -1,4 +1,4 @@
-= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ }
+= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ, seen_at: seen_at }
 
 = form.email_field :value,
   placeholder: champ.libelle,
diff --git a/app/views/new_gestionnaire/dossiers/champs/_engagement.html.haml b/app/views/new_gestionnaire/dossiers/champs/_engagement.html.haml
index 2668405ba..882404c2e 100644
--- a/app/views/new_gestionnaire/dossiers/champs/_engagement.html.haml
+++ b/app/views/new_gestionnaire/dossiers/champs/_engagement.html.haml
@@ -1,4 +1,4 @@
-= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ }
+= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ, seen_at: seen_at }
 
 = form.check_box :value,
   { required: champ.mandatory },
diff --git a/app/views/new_gestionnaire/dossiers/champs/_multiple_drop_down_list.html.haml b/app/views/new_gestionnaire/dossiers/champs/_multiple_drop_down_list.html.haml
index 5f0fb9439..cc8617eaf 100644
--- a/app/views/new_gestionnaire/dossiers/champs/_multiple_drop_down_list.html.haml
+++ b/app/views/new_gestionnaire/dossiers/champs/_multiple_drop_down_list.html.haml
@@ -1,4 +1,4 @@
-= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ }
+= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ, seen_at: seen_at }
 
 - if champ.drop_down_list && champ.drop_down_list.options.any?
   = form.select :value,
diff --git a/app/views/new_gestionnaire/dossiers/champs/_number.html.haml b/app/views/new_gestionnaire/dossiers/champs/_number.html.haml
index c9bcb8eae..f020980b9 100644
--- a/app/views/new_gestionnaire/dossiers/champs/_number.html.haml
+++ b/app/views/new_gestionnaire/dossiers/champs/_number.html.haml
@@ -1,4 +1,4 @@
-= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ }
+= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ, seen_at: seen_at }
 
 = form.number_field :value,
   placeholder: champ.libelle,
diff --git a/app/views/new_gestionnaire/dossiers/champs/_pays.html.haml b/app/views/new_gestionnaire/dossiers/champs/_pays.html.haml
index cad18df07..f52c146e9 100644
--- a/app/views/new_gestionnaire/dossiers/champs/_pays.html.haml
+++ b/app/views/new_gestionnaire/dossiers/champs/_pays.html.haml
@@ -1,4 +1,4 @@
-= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ }
+= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ, seen_at: seen_at }
 
 = form.select :value,
   Champ.pays,
diff --git a/app/views/new_gestionnaire/dossiers/champs/_phone.html.haml b/app/views/new_gestionnaire/dossiers/champs/_phone.html.haml
index e42dbfad1..7888eff8c 100644
--- a/app/views/new_gestionnaire/dossiers/champs/_phone.html.haml
+++ b/app/views/new_gestionnaire/dossiers/champs/_phone.html.haml
@@ -1,4 +1,4 @@
-= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ }
+= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ, seen_at: seen_at }
 
 = form.phone_field :value,
   placeholder: champ.libelle,
diff --git a/app/views/new_gestionnaire/dossiers/champs/_regions.html.haml b/app/views/new_gestionnaire/dossiers/champs/_regions.html.haml
index eb9ffaf8d..5946d812c 100644
--- a/app/views/new_gestionnaire/dossiers/champs/_regions.html.haml
+++ b/app/views/new_gestionnaire/dossiers/champs/_regions.html.haml
@@ -1,4 +1,4 @@
-= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ }
+= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ, seen_at: seen_at }
 
 = form.select :value,
   Champ.regions,
diff --git a/app/views/new_gestionnaire/dossiers/champs/_text.html.haml b/app/views/new_gestionnaire/dossiers/champs/_text.html.haml
index 2e34ffa6c..bef083c2f 100644
--- a/app/views/new_gestionnaire/dossiers/champs/_text.html.haml
+++ b/app/views/new_gestionnaire/dossiers/champs/_text.html.haml
@@ -1,4 +1,4 @@
-= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ }
+= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ, seen_at: seen_at }
 
 = form.text_field :value,
   placeholder: champ.libelle,
diff --git a/app/views/new_gestionnaire/dossiers/champs/_textarea.html.haml b/app/views/new_gestionnaire/dossiers/champs/_textarea.html.haml
index 5e2b2164c..4b3b832c8 100644
--- a/app/views/new_gestionnaire/dossiers/champs/_textarea.html.haml
+++ b/app/views/new_gestionnaire/dossiers/champs/_textarea.html.haml
@@ -1,4 +1,4 @@
-= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ }
+= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ, seen_at: seen_at }
 
 ~ form.text_area :value,
   row: 6,
diff --git a/app/views/new_gestionnaire/dossiers/champs/_yes_no.html.haml b/app/views/new_gestionnaire/dossiers/champs/_yes_no.html.haml
index 7893c60b8..9daf80548 100644
--- a/app/views/new_gestionnaire/dossiers/champs/_yes_no.html.haml
+++ b/app/views/new_gestionnaire/dossiers/champs/_yes_no.html.haml
@@ -1,4 +1,4 @@
-= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ }
+= render partial: 'new_gestionnaire/dossiers/champs/champ_label', locals: { form: form, champ: champ, seen_at: seen_at }
 
 .radios
   %label
diff --git a/app/views/new_gestionnaire/dossiers/messagerie.html.haml b/app/views/new_gestionnaire/dossiers/messagerie.html.haml
index b7423effc..5dac5390a 100644
--- a/app/views/new_gestionnaire/dossiers/messagerie.html.haml
+++ b/app/views/new_gestionnaire/dossiers/messagerie.html.haml
@@ -6,6 +6,6 @@
   %ul.messages-list
     - @dossier.commentaires.each do |commentaire|
       %li
-        = render partial: "new_gestionnaire/shared/commentaires/commentaire", locals: { commentaire: commentaire }
+        = render partial: "new_gestionnaire/shared/commentaires/commentaire", locals: { commentaire: commentaire, messagerie_seen_at: @messagerie_seen_at }
 
   = render partial: "new_gestionnaire/shared/commentaires/form", locals: { commentaire: @commentaire, form_url: commentaire_dossier_path(@dossier.procedure, @dossier) }
diff --git a/app/views/new_gestionnaire/dossiers/print.html.haml b/app/views/new_gestionnaire/dossiers/print.html.haml
index d557a198e..1f4d1025a 100644
--- a/app/views/new_gestionnaire/dossiers/print.html.haml
+++ b/app/views/new_gestionnaire/dossiers/print.html.haml
@@ -13,7 +13,7 @@
 
 - champs = @dossier.ordered_champs.decorate
 - if champs.any?
-  = render partial: "champs", locals: { champs: champs }
+  = render partial: "champs", locals: { champs: champs, dossier: @dossier }
 
 - if @dossier.procedure.use_api_carto
   %h3 Cartographie
diff --git a/app/views/new_gestionnaire/dossiers/show.html.haml b/app/views/new_gestionnaire/dossiers/show.html.haml
index 0519f69f5..efae124ec 100644
--- a/app/views/new_gestionnaire/dossiers/show.html.haml
+++ b/app/views/new_gestionnaire/dossiers/show.html.haml
@@ -15,7 +15,7 @@
   - champs = @dossier.ordered_champs.includes(:type_de_champ).decorate
   - if champs.any?
     .card
-      = render partial: "champs", locals: { champs: champs }
+      = render partial: "champs", locals: { champs: champs, dossier: @dossier, demande_seen_at: @demande_seen_at }
 
   - if @dossier.procedure.use_api_carto
     .accompagnateur-title Cartographie
@@ -25,4 +25,4 @@
   - if @dossier.procedure.cerfa_flag? || @dossier.types_de_piece_justificative.any?
     .accompagnateur-title Pièces jointes
     .card
-      = render partial: "pieces_jointes", locals: { dossier: @dossier }
+      = render partial: "pieces_jointes", locals: { dossier: @dossier, demande_seen_at: @demande_seen_at }
diff --git a/app/views/new_gestionnaire/shared/commentaires/_commentaire.html.haml b/app/views/new_gestionnaire/shared/commentaires/_commentaire.html.haml
index d3cbb9610..5de924c4f 100644
--- a/app/views/new_gestionnaire/shared/commentaires/_commentaire.html.haml
+++ b/app/views/new_gestionnaire/shared/commentaires/_commentaire.html.haml
@@ -4,9 +4,10 @@
   %h2
     %span.mail
       = render partial: 'new_gestionnaire/shared/commentaires/commentaire_issuer', locals: { commentaire: commentaire, current_gestionnaire: current_gestionnaire }
-    - if ![current_gestionnaire.email, @dossier.user.email, 'contact@tps.apientreprise.fr'].include?(commentaire.email)
+    - if ![current_gestionnaire.email, commentaire.dossier.user.email, 'contact@tps.apientreprise.fr'].include?(commentaire.email)
       %span.guest Invité
-    %span.date= I18n.l(commentaire.created_at.localtime, format: '%H:%M le %d/%m/%Y')
+    %span.date{ class: highlight_if_unseen_class(messagerie_seen_at, commentaire.created_at) }
+      = I18n.l(commentaire.created_at.localtime, format: '%d/%m/%Y à %H:%M ')
   .rich-text= sanitize(commentaire.body)
 
   - if commentaire.piece_justificative
diff --git a/app/views/root/patron.html.haml b/app/views/root/patron.html.haml
index 27e3039cd..77288ecfc 100644
--- a/app/views/root/patron.html.haml
+++ b/app/views/root/patron.html.haml
@@ -23,8 +23,8 @@
       = form_for @dossier, url: '', html: { class: 'form' } do |f|
         = f.fields_for :champs do |champ_form|
           - champ = champ_form.object
-          = render partial: "new_gestionnaire/dossiers/champs/#{champ.type_champ}",
-            locals: { champ: champ, form: champ_form }
+          = render partial: "new_gestionnaire/dossiers/champs/champ",
+            locals: { champ: champ, form: champ_form, seen_at: nil }
 
         %input{ type: "password", value: "12345678" }
         .send-wrapper
diff --git a/spec/helpers/dossier_helper_spec.rb b/spec/helpers/dossier_helper_spec.rb
new file mode 100644
index 000000000..0ceec6d96
--- /dev/null
+++ b/spec/helpers/dossier_helper_spec.rb
@@ -0,0 +1,28 @@
+require 'rails_helper'
+
+RSpec.describe DossierHelper, type: :helper do
+  describe ".highlight_if_unseen_class" do
+    let(:seen_at) { DateTime.now }
+
+    subject { highlight_if_unseen_class(seen_at, updated_at) }
+
+    context "when commentaire date is created before last seen datetime" do
+      let(:updated_at) { seen_at - 2.days }
+
+      it { is_expected.to eq nil }
+    end
+
+    context "when commentaire date is created after last seen datetime" do
+      let(:updated_at) { seen_at + 2.hours }
+
+      it { is_expected.to eq "highlighted" }
+    end
+
+    context "when there is no last seen datetime" do
+      let(:updated_at) { DateTime.now }
+      let(:seen_at) { nil }
+
+      it { is_expected.to eq nil }
+    end
+  end
+end
diff --git a/spec/views/new_gestionnaire/avis/avis_list.html.haml_spec.rb b/spec/views/new_gestionnaire/avis/avis_list.html.haml_spec.rb
new file mode 100644
index 000000000..0a197e1a7
--- /dev/null
+++ b/spec/views/new_gestionnaire/avis/avis_list.html.haml_spec.rb
@@ -0,0 +1,20 @@
+describe 'new_gestionnaire/avis/avis_list.html.haml', type: :view do
+  before { view.extend DossierHelper }
+
+  subject { render 'new_gestionnaire/avis/avis_list.html.haml', avis: avis, avis_seen_at: seen_at, current_gestionnaire: gestionnaire }
+
+  let(:gestionnaire) { create(:gestionnaire) }
+  let(:avis) { [create(:avis, claimant: gestionnaire)] }
+
+  context "with a seen_at after avis created_at" do
+    let(:seen_at) { avis.first.created_at + 1.hour }
+
+    it { is_expected.not_to have_css(".highlighted") }
+  end
+
+  context "with a seen_at after avis created_at" do
+    let(:seen_at) { avis.first.created_at - 1.hour }
+
+    it { is_expected.to have_css(".highlighted") }
+  end
+end
diff --git a/spec/views/new_gestionnaire/dossiers/_champs.html.haml_spec.rb b/spec/views/new_gestionnaire/dossiers/_champs.html.haml_spec.rb
index 91075ffa1..21925c3f9 100644
--- a/spec/views/new_gestionnaire/dossiers/_champs.html.haml_spec.rb
+++ b/spec/views/new_gestionnaire/dossiers/_champs.html.haml_spec.rb
@@ -1,12 +1,14 @@
 describe 'new_gestionnaire/dossiers/champs.html.haml', type: :view do
   let(:gestionnaire) { create(:gestionnaire) }
+  let(:demande_seen_at) { nil }
 
   before do
+    view.extend DossierHelper
     view.extend DossierLinkHelper
     allow(view).to receive(:current_gestionnaire).and_return(gestionnaire)
   end
 
-  subject { render 'new_gestionnaire/dossiers/champs.html.haml', champs: champs }
+  subject { render 'new_gestionnaire/dossiers/champs.html.haml', champs: champs, demande_seen_at: demande_seen_at }
 
   context "there are some champs" do
     let(:dossier) { create(:dossier) }
@@ -48,4 +50,22 @@ describe 'new_gestionnaire/dossiers/champs.html.haml', type: :view do
 
     it { is_expected.to include("Pas de dossier associé") }
   end
+
+  context "with seen_at" do
+    let(:dossier) { create(:dossier) }
+    let(:champ1) { create(:champ, :checkbox, value: "true") }
+    let(:champs) { [champ1] }
+
+    context "with a demande_seen_at after champ updated_at" do
+      let(:demande_seen_at) { champ1.updated_at + 1.hour }
+
+      it { is_expected.not_to have_css(".highlighted") }
+    end
+
+    context "with a demande_seen_at after champ updated_at" do
+      let(:demande_seen_at) { champ1.updated_at - 1.hour }
+
+      it { is_expected.to have_css(".highlighted") }
+    end
+  end
 end
diff --git a/spec/views/new_gestionnaire/dossiers/show.html.haml_spec.rb b/spec/views/new_gestionnaire/dossiers/show.html.haml_spec.rb
index 68ad70c78..966912d4f 100644
--- a/spec/views/new_gestionnaire/dossiers/show.html.haml_spec.rb
+++ b/spec/views/new_gestionnaire/dossiers/show.html.haml_spec.rb
@@ -1,4 +1,6 @@
 describe 'new_gestionnaire/dossiers/show.html.haml', type: :view do
+  before { view.extend DossierHelper }
+
   let(:current_gestionnaire) { create(:gestionnaire) }
   let(:individual) { nil }
   let(:entreprise) { nil }
diff --git a/spec/views/new_gestionnaire/shared/commentaires/commentaire.html.haml_spec.rb b/spec/views/new_gestionnaire/shared/commentaires/commentaire.html.haml_spec.rb
new file mode 100644
index 000000000..e866a356d
--- /dev/null
+++ b/spec/views/new_gestionnaire/shared/commentaires/commentaire.html.haml_spec.rb
@@ -0,0 +1,22 @@
+describe 'new_gestionnaire/shared/commentaires/commentaire.html.haml', type: :view do
+  before { view.extend DossierHelper }
+
+  subject { render 'new_gestionnaire/shared/commentaires/commentaire.html.haml', commentaire: commentaire, messagerie_seen_at: seen_at, current_gestionnaire: current_gestionnaire }
+
+  let(:dossier) { create(:dossier) }
+  let(:commentaire) { create(:commentaire, dossier: dossier) }
+  let(:current_gestionnaire) { create(:gestionnaire) }
+  let(:seen_at) { commentaire.created_at + 1.hour }
+
+  context "with a seen_at after commentaire created_at" do
+    let(:seen_at) { commentaire.created_at + 1.hour  }
+
+    it { is_expected.not_to have_css(".highlighted") }
+  end
+
+  context "with a seen_at after commentaire created_at" do
+    let(:seen_at) { commentaire.created_at - 1.hour  }
+
+    it { is_expected.to have_css(".highlighted") }
+  end
+end