Synopsis
Recognise the distinctive follicular, palmoplantar and island-sparing pattern of pityriasis rubra pilaris, confirm rare disease thoughtfully, protect erythrodermic physiology, and refer for specialist treatment.
- PRP is a rare inflammatory keratinisation disorder characterised by rough follicular papules, coalescing orange-red or brown-red scaly plaques, islands of sparing and waxy palmoplantar keratoderma.
- Classic adult PRP often starts on scalp or face and spreads downwards; orange colour may be subtle in deeply pigmented skin, so texture, follicular plugging and spared islands are more reliable.
- Palms and soles become thick, orange or waxy and fissured; pain, walking and hand function are essential severity outcomes.
- Diagnosis is clinical with dermatology confirmation; biopsy can support the pattern and exclude psoriasis, drug eruption or lymphoma, but no blood test confirms PRP.
- Classic adult type has the most favourable natural history, with BAD reporting spontaneous clearance in up to 80% within three years, while atypical and familial forms may persist.
- Limited disease uses regular emollient, keratolytic and site-appropriate topical corticosteroid for symptoms; these may reduce inflammation without shortening the whole disease course.
- Extensive disease requires specialist treatment, commonly off-label acitretin or methotrexate and sometimes phototherapy or biologic therapy after careful diagnosis and monitoring.
- Erythroderma with shivering, fluid loss or systemic instability requires immediate same-day specialist assessment and acute barrier-failure care.
Key red flags
Near-total skin inflammation with shivering, fever or hypothermia, tachycardia, oedema, reduced urine output or breathlessness requires emergency assessment.
Skin pain, mucosal erosions, dusky targets, blistering or a recent high-risk medicine suggests severe drug reaction rather than uncomplicated PRP.
Rapidly spreading warmth, purpura, focal disproportionate pain or haemodynamic compromise raises concern for invasive infection and needs immediate sepsis and surgical assessment.
Marked palmoplantar fissuring that prevents walking or hand use, nutritional compromise or severe distress warrants expedited specialist support even without erythroderma.
Near-total involvement with shivering, temperature change, oedema, tachycardia, oliguria or breathlessness indicates barrier failure and needs immediate acute care.
Investigation priorities
Identify follicular papules, direction of spread, islands of sparing, palmoplantar keratoderma and features of competing erythrodermas.
Management branches
Follicular papules, spared islands and palmoplantar keratoderma suggest PRP without physiological instability.
- Document onset, direction of spread, family and medicine history, HIV risk, full morphology and functional impact across skin tones.
- Refer to dermatology for confirmation and select a representative biopsy when psoriasis, drug eruption, lymphoma or inherited keratinisation disease remains plausible.
- Explain uncertainty and natural history honestly: classic adult disease often clears spontaneously, but subtype and treatment response vary and review may refine the label.