A 40-year-old man was presented with 8 years of multiple red scaly rashes on his arms, legs and trunk that had increased and clumped together to form groups of reddish patches. Patient lamented of a moderate itch.
Patient recalled that a solitary scaly rash had first appeared on his upper trunk 8 years ago, with multiple patches appearing on his arms and legs the few weeks following. He was diagnosed with plaque psoraisis and was given Hydrocortisone cream which was able to subside most of the rashes. However, the rashes reappeared after the cream ran out of stock. Another dermatologist prescribed Betamethasone Valerate which resolved the rashes intermittently but successively returned. He had been applying various steroids cream administrated by many dermotologists and family doctors, but the rashes and itches came and went periodically.
Even Ayurvedic Homeopathic therapy and TCM medicine proved ineffective.
Recently, a dermotologist recommend narrowband ultraviolet phototherapy and Methotrexate.
He has no other medical history. Recent serum laboratory tests showed no abnormalities. Serological tests for syphilis were negative. Tumor markers were within normal range.
Patient came to seek a third opinion. Dermatological examination revealed a partly confluent, coarse scaling exanthema on the trunk, with multiple erythematous scaly plaques on the extremities (Fig. Baseline). The nails of his fingers and toes were normal. Between the extensive lesions on his back, we observed numerous areas of uninvolved skin — islands of sparing. We diagnosed a Pityriasis rubra pilaris PRP (Fig. Baseline) rather than psoraisis, and advised histological study of skin biopsies to aid in the final diagnosis, but the patient rejected the skin biopsy procedure and was willing to start herbal therapy immetiately, as he fully understood that same immunosuppressants (steroids, phototherapy, MTX, Cyclosporine) would have been given to him no matter what dieases he would have been diagnosed with, no matter PRP or psoriasis, if he had gone for conventional western treatment.
The rash was provoked by the withdrawal of prior steroids. Patient experienced the rebound phenomenon (Fig. Month 3). Flare-up wave occured especially on the skin areas where the corticosteroid cream was frequently applied (Fig. Month 3). Over the next two months, the dead crusts and scaling skin was exfoliated from the trunk area (Fig. Month 6). The rash resolved completely 24 months after its initial presentation. We followed up after 12 months following the discontinuation of herbal therapy and no relapse was observed.
Pityriasis rubra pilaris (PRP) was first described in 1835 by Claudius Tarral as a variant of psoriasis. Devergie  later recognized it as a separate entity in 1857 and named it “pityriasis pilaris”. In 1889, Besnier  recommended the name “pityriasis rubra pilaris”, and it has persisted.
Most cases are acquired, but there are familial forms . Both autosomal dominant and less frequently autosomal recessive inheritance patterns have been described. The dominantly inherited form of PRP is associated with heterozygous gain-of-function mutations in CARD14, also known as the PSORS2 psoriasis susceptibility gene . Except for the latter group of patients and those with the non-classic forms, PRP appears to be a self-limited disease process, resolving within 3 to 5 years in almost all cases. However the above patient was either resistant to conventional immunosuppressive therapy or self resolved in the past 8 years. He may belong to the non-classic PRP group.
- A Devergie: Pityriasis pilaris. Traite pratique des maladies de la peau. 2nd ed 1857 Martinet Paris 454-464
- E Besnier: Du pityriasis rubra pilaire. Ann Dermatol Syphiligr (Paris). 10:253-287 1889
- MR Albert, BT Mackool: Pityriasis rubra pilaris. Int J Dermatol. 38:1-11 1999
- D Fuchs-Telem, O Sarig, MA van Steensel, et al.: Familial pityriasis rubra pilaris is caused by mutations in CARD14. Am J Hum Genet. 91:163-170 2012