KEGG :
36
Pityriasis rubra pilaris (PRP) is a spectrum of rare chronic inflammatory disorders with papulosquamous eruptions of unknown cause. The prototypical clinical characteristics of PRP are follicular hyperkeratotic papules on an erythematous base that can eventually coalesce to large red plaques. Its classification into five subgroups is based on age at onset, clinical course, morphologic features, and prognosis. More than 50% of patients are best classified as type I with adult-onset PRP. It is comprised of widespread, follicular papules and plaques and tends to clear spontaneously in 80% of patients in one to three years. Type II, which is the atypical adult subtype, tends to be more chronic and presents with areas of alopecia, eczematous patches, and a palmoplantar keratoderma. The classic juvenile type III is observed in only 10% of patients. It is similar clinically to type I but occurs in children and tends to remit in one year. Type IV, which is the circumscribed, juvenile subtype, presents with sharply-demarcated areas of follicular hyperkeratosis and erythema of the elbows and knees. An estimated 5% of children with PRP develop an atypical form classified as juvenile type V. Most familial cases that are published belong to this group. Recently, the designation of a new category of PRP (type VI) has been proposed that is characterized by the presence of HIV infection with different clinical features and a poorer prognosis. Treatment of PRP can be difficult, and no standardized approach has been established, although systemic retinoids are considered first-line therapy. Cyclosporin, methotrexate, and azathioprine are alternatives.
MalaCards based summary :
Pityriasis Rubra Pilaris, also known as
prp, is related to
familial pityriasis rubra pilaris and
pustular psoriasis. An important gene associated with Pityriasis Rubra Pilaris is
CARD14 (Caspase Recruitment Domain Family Member 14), and among its related pathways/superpathways are
T cell receptor signaling pathway and
NF-kappaB Signaling. The drugs
Salicylic acid and
Dermatologic Agents have been mentioned in the context of this disorder. Affiliated tissues include
skin,
t cells and
thyroid, and related phenotypes are
papule and
palmoplantar keratoderma
NIH Rare Diseases :
52
Pityriasis rubra pilaris (PRP) refers to a group of skin conditions that cause constant inflammation and scaling of the skin. People with PRP have reddish, scaly patches that may occur everywhere on the body, or only on certain areas. Some people with PRP also develop thickened skin on the underside of the hands and feet (palmoplantar keratoderma ), various nail abnormalities, and/or thinning of the hair. There are several types of PRP classified by age when symptoms begin, body areas involved, and whether other conditions are present. This condition occurs in adults (adult onset PRP) as well as children (juvenile onset PRP). In most cases, PRP is not inherited and the cause is not known. In some people, particularly some with type V (the "atypical juvenile type"), PRP has autosomal dominant inheritance and may be caused by mutations in the CARD14 gene . Treatment options vary based on symptoms and severity. No one treatment works for all people with PRP. Examples of treatment options include topical emollients or medications, oral retinoids , and/or immunosuppressants .
OMIM :
56
Pityriasis rubra pilaris is an uncommon skin disorder characterized by the appearance of keratotic follicular papules, well-demarcated salmon-colored erythematous plaques covered with fine powdery scales interspersed with distinct islands of uninvolved skin, and palmoplantar keratoderma. Most cases are sporadic, although up to 6.5% of PRP-affected individuals report a positive family history. The rare familial cases show autosomal dominant inheritance with incomplete penetrance and variable expression: the disorder is usually present at birth or appears during the first years of life and is characterized by prominent follicular hyperkeratosis, diffuse palmoplantar keratoderma, and erythema, with only a modest response to treatment (summary by Fuchs-Telem et al., 2012).
(173200)
UniProtKB/Swiss-Prot :
73
Pityriasis rubra pilaris: A rare, papulosquamous skin disease characterized by the appearance of keratotic follicular papules, well-demarcated salmon-colored erythematous plaques covered with fine powdery scales interspersed with distinct islands of uninvolved skin, and palmoplantar keratoderma. Most cases are sporadic. The rare familial cases show autosomal dominant inheritance with incomplete penetrance and variable expression. Familial PRP usually presents at birth or appears during the first years of life and runs a chronic course. It is characterized by prominent follicular hyperkeratosis, diffuse palmoplantar keratoderma, and erythema.
Wikipedia :
74
Pityriasis rubra pilaris refers to a group of chronic disorders characterized by reddish orange, scaling...
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Rare skin diseases 
