Fifty-seven patients with pityriasis rubra pilaris (PRP), including 16 children and 41 adults, were studied by personal examination or by questionnaire.
Forty-nine percent (29 of 57) of all patients had no evidence of this disease after an average duration of 2.3 years (range 3 months to 7 years). Seven of 16 (44%) of those with PRP of childhood onset and 21 of 41 (51%) of those with disease of adult onset became free of symptoms.
As compared to the 17 of 24 adults with typical disease that cleared, only 4 of 17 adults with atypical disease had clearing. Despite the similar ages at onset, these two groups are different.
With the exception of the four patients treated with systemically administered methotrexate, patients who became symptom-free had the lesions clear regardless of the therapy used. There was no unanimity of opinion among patients regarding which therapy was most effective, or, in fact, if treatment was useful.
Davidson CL, Winkelmann RK, Kierland RR. Pityriasis Rubra PilarisA Follow-up Study of 57 Patients. Arch Dermatol. 1969;100(2):175-178. doi:10.1001/archderm.1969.01610260051008