[考生加油] Dermatological Recall: Chapter 29 Pityriasis Rubra Pilaris(PRP)

美國有一系列醫學教科書稱為「回憶系列(Recall Series)」，包括了內外婦兒急診科的臨床知識，甚至有出病理科與影像科等二線科別的用書。這套教科書都用問答的方式來描述專科的醫學知識，和傳統教科書大相逕庭，看起來很奇怪。

經過回想過的記憶才會長久留存！

神奇的是：當年大五的我自己遮住答案回答完後，還真的把這些複雜的知識都記住了。因此有次教化學家教時，就照這種方式把整個章節「問了」學生一次，結果效果好到懷疑人生(如果當年我知道可以這樣做...)。考量皮膚科沒有出這種教科書，因此煜彬決定自己來纂寫這些章節。

Chapter 29 :: Pityriasis Rubra Pilaris(PRP) 

:: Knut Schäkel

鄭煜彬 整理 20191209

EPIDEMIOLOGY
How much is the male-to-female ratio of PRP?	M=F
CLINICAL FEATURES
Which 2 features helps to classify PRP?	1.      Age of onset (adult or juvenile) 2.      Course/prognosis (classic or atypical).
What are the six types of PRP?	1.      Classic adult (I) 2.      Atypical adult (II) 3.      Classic juvenile (III) 4.      Circumscribed juvenile (IV) 5.      Atypical juvenile, CARD 14 mutation (V) HIV-associated (VI)
What are the first 3 common types of PRP & the ranking ?	1.      Classic adult (>50%) 2.      Circumscribed juvenile (25%) 6.      Classic juvenile (10%)
Why PRP is difficult to diagnose in the beginning?	3.      It looks like scaly dermatitis (well-defined, yellow-orange). (However, it may spread to erythroderma in 2-3 months)
What is the 2 common features of PRP?	1.      Salmon-colored scaly plaques 2.      Follicular hyperkeratosis
What are the 3 morphological features of Type I PRP?	1.      Erythroderma with nappes claires 2.      Follicular hyperkeratosis 3.      Waxy diffuse palmoplantar keratosis
What are the 3 morphological features of Type II PRP?	1.      Follicular hyperkeratosis 2.      Sparse scalp hair 4.      Ichthyosiform lesions on legs
What are the 3 morphological features of Type III PRP?	1.      Erythroderma with nappes claires 2.      Follicular hyperkeratosis 3.      Waxy diffuse palmoplantar keratosis (as Type I PRP, but earlier onset)
What are the morphological features of Type IV PRP?	Well-demarcated scaly, erythematous plaques at elbow & knee (as psoriasis)
What are the 3 morphological features of Type V PRP?	1.      Familial cases 2.      Follicular hyperkeratosis Scleroderma-like palms & soles
What are the 3 associated features of Type VI PRP?	1.      Acne conglobate 2.      Hidradenitis suppurativa 3.      Lichen spinulosus 3.      (as Type I PRP, but HIV+)
What is the age of onset of Type I-VI PRP?	I-II: adulthood III-V: children & adolescents VI: all ages.
What is the distribution of Type I-VI PRP?	IV: localized Others: generalized, head/neck→caudal
What is course of Type I-V PRP?	I & III: classic, short, < 3 year, usually 1-2 years. II & V: atypical, long, > 20 years. IV: uncertain, may resolve in teens.
ETIOLOGY
What is the most possible etiology of sporadic PRP?	Infections, such as upper respiratory tract infections
What is the only 2 confirmed etiologies of PRP up to now?	1.      CARD 14(Caspase Recruitment Domain family member 14), gain of function mutation (in familial cases/type V) 2.      HIV infection(type VI)
What is the mechanism of CARD 14 mutation in PRP type V?	CARD 14 mutation→↑CARD 14→activate NF-κB signaling→activate p65
What is the changes of cytokines in PRP lesions?	1.      ↑proinflammatory innate cytokines: TNF, IL-6, 12, 23, & IL-1β 2.      ↑ TH1 cytokines 3.      ↑ TH17 cytokines(IL-17A/F, & 22)
DIFFERENTIAL DIAGNOSIS
What is the major differential  diagnosis of PRP?	Psoriasis
What is the clinical difference between psoriasis & PRP?	Psoriasis: extensor, Koebner sign, plaques with white scales (candle sign), Auspitz sign PRP: head, salmon-color, islands of healthy skin, follicular hyperkeratosis, waxy PPK
What is the difference between the nail of psoriasis and PRP?	Psoriasis: salmon patch, oil spot, pitting, subungual hyperkeratosis, onycholysis… PRP: only hypertrophic nail plate
What is the histologic difference between psoriasis and PRP	Psoriasis: hypogranulosis, elongated rete ridges, vascular dilation, intraepidermal Munro microabscesses. PRP: alternating horizontal/vertical para-/ortho-keratosis, hypergranulosis, thickening rete ridges, follicular hyperkeratosis
TREATMENTS
What are the effective first-line treatments of PRP?	Topical: emollients, keratolytic(salicylic acid), vit. D3 analogs(calcipotriol) Systemic: retinoids, methotrexate, anti-retroviral tx.
What are the effective second-line treatments of PRP?	Topical: corticosteroids, calcineurin inhibitors, tazarotene Systemic: fumaric acid esters, apremilast, TNF inhibitors, anti-IL-12/IL-23p40, anti-IL-17, azathioprine, cyclosporine Phototherapy: PUVA, Re-PUVA, UVA1, NBUVB, BBUVB, Extracorporeal photopheresis
Which disease has treatments similar to PRP?	Psoriasis(almost the same)
What is the restriction of the use of vit. D3 analogs?	No more than 30% BSA.
What is the dose of oral methotrexate for PRP?	10-25mg/week
What is the choice & dose of oral retinoids ?	Acitretin(0.5-0.75mg/kg/day), isotretinoin(1-2mg/kg/day), alitretinoin.
What is the side effects of retinoids for the prepubertal?	Premature closure of epiphyses & hyperostosis
What should you do before the phototherapy?	Phototesting, because phototherapy may aggravate PRP.
Which type of PRP does not response to ustekinumab?	Type IV PRP
What is the most effective treatment of type VI PRP?	triple antiretroviral therapy