Pityriasis rubra pilaris: A review

Pityriasis rubra pilaris (PRP, syn.: Devergie's disease) is a rare idiopathic papulo-squamous inflammatory skin disease characterized by follicular papules, palmar-plantar keratoderma, scaling plaques of orange-red color with characteristic foci of unaffected skin. Histologically, the alternating pattern of orthokeratosis and parakeratosis is considered a distinctive feature of PRP (staggered hyperkeratosis). A violation of the regulation of innate immunity is a component of the pathogenesis of PRP. Congenital mutations of CARD 14 or concomitant antigens, which can take the form of iatrogenic lesions, infections or malignant neoplasms, can be the initial triggers of the disease, although the etiology is often idiopathic. There are classically five subtypes of the disease, depending on the age of onset and clinical picture. Type VI PRP is associated with infection caused by the human immunodeficiency virus. CARD 14-associated papulosquamous rash and discoid dermatitis of the face represent new clinical phenotypes of PRP. Devergie's disease has a pronounced negative impact on the quality of life, and those who become ill are at increased risk of depression and suicide. Ixekizumab, methotrexate and secukinumab can be considered as systemic drugs of the first choice. If there is a contraindication to immunosuppressive therapy, high doses of isotretinoin are recommended. Topical agents, including calcipotriene, calcineurin inhibitors, emollients and topical corticosteroids, are used as additional therapy.