{"id":116,"date":"2026-02-01T18:18:57","date_gmt":"2026-02-01T17:18:57","guid":{"rendered":"https:\/\/erlaxatu.fr\/?page_id=116"},"modified":"2026-02-01T18:18:58","modified_gmt":"2026-02-01T17:18:58","slug":"horton-ppr","status":"publish","type":"page","link":"https:\/\/erlaxatu.fr\/index.php\/horton-ppr\/","title":{"rendered":"Horton PPR"},"content":{"rendered":"<p><strong>Pseudopolyarthrite rhizom\u00e9lique (PPR) et Art\u00e9rite \u00e0 cellules g\u00e9antes (ACG\/Horton)<\/strong><\/p>\n<p><strong>I. \u00c9pid\u00e9miologie commune (rep\u00e8res)<\/strong><\/p>\n<p>Apr\u00e8s 50 ans, pic 70\u201380 ans ; PPR 3 \u00e0 10\u00d7 plus fr\u00e9quente ; sex-ratio ~2F\/1H ; gradient Nord\u2192Sud Europe ; rare chez Asiatiques\/Africains.<\/p>\n<p><strong>II. PPR (pseudopolyarthrite rhizom\u00e9lique)<\/strong><\/p>\n<p><strong>A. Examens compl\u00e9mentaires utiles (\u00e0 adapter)<\/strong><\/p>\n<ul>\n<li>Biologie : NFS, CRP\/VS, glyc\u00e9mie, \u03b3GT\/transaminases, CPK, calc\u00e9mie, FR\/anti-CCP, \u00b1 TSH\/autoanticorps myosites selon contexte.<\/li>\n<li>Imagerie : Rx \u00e9paules\/bassin (\u00b1 mains), \u00b1 Rx thorax\/ost\u00e9odensitom\u00e9trie, \u00e9chographie \u00e9paules\/bassin (bursite sub-acromio-delto\u00efdienne volontiers bilat\u00e9rale\/sym\u00e9trique).<\/li>\n<\/ul>\n<p><strong>B. Points d\u2019attention (iatrog\u00e9nie \/ diagnostics diff\u00e9rentiels)<\/strong><\/p>\n<p>Des m\u00e9dicaments peuvent mimer ou d\u00e9clencher des myalgies\/syndromes type PPR : statines, b\u00eatabloquants, antiparkinsoniens, inhibiteurs de checkpoints (ipilimumab, nivolumab). Penser aussi Parkinson, dysthyro\u00efdies, ost\u00e9omalacie.<\/p>\n<p><strong>C. Traitement (rep\u00e8res concrets)<\/strong><\/p>\n<ul>\n<li>Prednisone PO : dose moyenne <strong>15 mg\/j<\/strong> (\u22480,3 mg\/kg\/j), adaptable <strong>12,5 \u00e0 30 mg\/j<\/strong> selon sympt\u00f4mes\/poids\/comorbidit\u00e9s, maintenue jusqu\u2019\u00e0 disparition clinique + syndrome inflammatoire.<\/li>\n<li>Efficacit\u00e9 souvent spectaculaire en 24\u201372 h, souvent utilis\u00e9e comme argument diagnostique (mais attention : r\u00e9ponse possible dans d\u2019autres pathologies inflammatoires).<\/li>\n<li>Dur\u00e9e moyenne : 12\u201324 mois ; d\u00e9croissance progressive et individualis\u00e9e.<\/li>\n<\/ul>\n<p><strong>III. ACG \/ maladie de Horton<\/strong><\/p>\n<p><strong>A. D\u00e9finition<\/strong><\/p>\n<p>Vascularite syst\u00e9mique primitive : <strong>panart\u00e9rite<\/strong> segmentaire et focale des art\u00e8res de grand et moyen calibre, touchant pr\u00e9f\u00e9rentiellement branches de la carotide externe (temporales\/occipitales) et pouvant atteindre art\u00e8res ophtalmiques, vert\u00e9brales, subclavi\u00e8res\/axillaires, aorte. Urgence diagnostique et th\u00e9rapeutique (risque d\u2019occlusion).<\/p>\n<p><strong>B. Signes cliniques majeurs \u00e0 rechercher<\/strong><\/p>\n<ul>\n<li>Douleur sur trajet des art\u00e8res temporales (induration, diminution\/abolition du pouls).<\/li>\n<li>Claudication de la m\u00e2choire\/langue (douleur \u00e0 la mastication), rares n\u00e9croses.<\/li>\n<li><strong>Signes ophtalmologiques = urgence<\/strong> : baisse d\u2019acuit\u00e9 visuelle brutale indolore, flou visuel, diplopie, amaurose.<\/li>\n<\/ul>\n<p><strong>C. Complications (gravit\u00e9)<\/strong><\/p>\n<p>Complications surtout isch\u00e9miques, brutales, parfois irr\u00e9versibles :<\/p>\n<ul>\n<li>Oculaires (5\u201320%) : c\u00e9cit\u00e9 monoculaire brutale, parfois prodromes (flou\/scotome\/diplopie) ; 1\u20132% c\u00e9cit\u00e9 bilat\u00e9rale d\u00e9finitive.<\/li>\n<li>Neurologiques : AVC\/AIT (~5%).<\/li>\n<li>Manifestations neuropsy : d\u00e9sorientation\/troubles de l\u2019humeur (~3%), r\u00e9pondant souvent \u00e0 la corticoth\u00e9rapie.<\/li>\n<\/ul>\n<p><strong>D. Imagerie et histologie<\/strong><\/p>\n<ul>\n<li>TEP-scan : examen de r\u00e9f\u00e9rence pour formes extracr\u00e2niales (cartographie vasculaire), non syst\u00e9matique.<\/li>\n<li><strong>Biopsie d\u2019art\u00e8re temporale (BAT)<\/strong> : r\u00e9f\u00e9rence pour confirmation ; ne doit <strong>pas retarder<\/strong> le traitement ; possible dans les <strong>14 jours<\/strong> apr\u00e8s d\u00e9but des cortico\u00efdes ; pr\u00e9l\u00e8vement \u22651 cm ; sensibilit\u00e9 ~50\u201391% (faux n\u00e9gatifs possibles).<\/li>\n<\/ul>\n<p><strong>E. Diagnostic diff\u00e9rentiel<\/strong><\/p>\n<p>Autres vascularites (Takayasu, GPA, PAN, Beh\u00e7et), infections (syphilis, tuberculose, salmonellose, endocardite), ath\u00e9roscl\u00e9rose, Erdheim-Chester, cancers, maladie associ\u00e9e aux IgG4.<\/p>\n<p><strong>IV. Traitement de la PPR et de l\u2019ACG (sch\u00e9ma \u201cpratico-pratique\u201d)<\/strong><\/p>\n<p><strong>A. Principes<\/strong><\/p>\n<ul>\n<li>Corticoth\u00e9rapie prolong\u00e9e : <strong>faible dose dans PPR<\/strong>, <strong>forte dose dans ACG<\/strong>.<\/li>\n<li>ACG : mise sous cortico\u00efdes = <strong>urgence<\/strong>, surtout si signes ophtalmo\/isch\u00e9miques.<\/li>\n<\/ul>\n<p><strong>B. Traitement d\u2019attaque (doses cl\u00e9s)<\/strong><\/p>\n<ul>\n<li><strong>PPR<\/strong> : prednisone ~15 mg\/j (12,5\u201330 mg\/j).<\/li>\n<li><strong>ACG sans signe oculaire\/c\u00e9r\u00e9bral<\/strong> : prednisone <strong>0,7 mg\/kg\/j<\/strong> \u00e0 d\u00e9buter rapidement.<\/li>\n<li><strong>ACG avec signe oculaire\/isch\u00e9mique<\/strong> : prednisone <strong>1 mg\/kg\/j<\/strong> en urgence, possibilit\u00e9 de pr\u00e9c\u00e9der par m\u00e9thylprednisolone IV (bolus discut\u00e9s, preuve limit\u00e9e). Certaines \u00e9quipes associent un antiagr\u00e9gant pr\u00e9ventif.<\/li>\n<\/ul>\n<p><strong>C. D\u00e9croissance et rechutes<\/strong><\/p>\n<ul>\n<li>D\u00e9croissance par paliers sur plusieurs mois (rep\u00e8res : -10 mg jusqu\u2019\u00e0 30 mg, puis -5 \u00e0 -2,5 mg jusqu\u2019\u00e0 10 mg, puis -1 mg toutes les 2\u20134 semaines), avec r\u00e9\u00e9valuation clinique + inflammation \u00e0 chaque \u00e9tape.<\/li>\n<li>Rechutes : 20\u201350% ; favoris\u00e9es par d\u00e9croissance trop rapide \/ mauvaise observance \/ pouss\u00e9e ; une rechute peut se pr\u00e9senter sous une autre forme (PPR \u2192 ACG).<\/li>\n<\/ul>\n<p><strong>D. Mesures associ\u00e9es (pr\u00e9vention iatrog\u00e8ne)<\/strong><\/p>\n<p>R\u00e9gime pauvre sel\/sucre, activit\u00e9 physique, vitamine D 800\u20131200 UI\/j (viser 25-OH-D &gt;30 ng\/ml), calcium seulement si apports alimentaires insuffisants, vaccinations (sans retarder la mise en route), pr\u00e9vention ost\u00e9oporose, surveillance TA\/poids\/\u0153d\u00e8mes\/glyc\u00e9mie\/dyslipid\u00e9mies\/cataracte\/glaucome, discussion antiagr\u00e9gant dans complications isch\u00e9miques.<\/p>\n<p><strong>E. Alternatives \/ \u00e9pargne cortisonique<\/strong><\/p>\n<ul>\n<li>M\u00e9thotrexate : utilis\u00e9 dans une logique d\u2019\u00e9pargne, mais preuve non d\u00e9finitive.<\/li>\n<li>Tocilizumab (anti-IL6R) : efficace dans ACG et PPR, AMM dans l\u2019ACG (2017), r\u00e9serv\u00e9 aux sp\u00e9cialistes, surtout si comorbidit\u00e9s rendant les cortico\u00efdes difficiles.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Pseudopolyarthrite rhizom\u00e9lique (PPR) et Art\u00e9rite \u00e0 cellules g\u00e9antes (ACG\/Horton) I. \u00c9pid\u00e9miologie commune (rep\u00e8res) Apr\u00e8s 50 ans, pic 70\u201380 ans ; [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"class_list":["post-116","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/erlaxatu.fr\/index.php\/wp-json\/wp\/v2\/pages\/116","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/erlaxatu.fr\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/erlaxatu.fr\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/erlaxatu.fr\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/erlaxatu.fr\/index.php\/wp-json\/wp\/v2\/comments?post=116"}],"version-history":[{"count":1,"href":"https:\/\/erlaxatu.fr\/index.php\/wp-json\/wp\/v2\/pages\/116\/revisions"}],"predecessor-version":[{"id":118,"href":"https:\/\/erlaxatu.fr\/index.php\/wp-json\/wp\/v2\/pages\/116\/revisions\/118"}],"wp:attachment":[{"href":"https:\/\/erlaxatu.fr\/index.php\/wp-json\/wp\/v2\/media?parent=116"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}