FIGURE 70.7 Pityriasis rosea with characteristic trailing edge scale within these oval papules and plaques PR is thought to be a reaction pattern to a preceding viral or other infectious process Reactivation of latent human herpesvirus or (HHV 6,7) has been postulated as one potential mechanism Given its clinical resemblance to secondary syphilis, adolescents and adults or those with risk factors for syphilis should be screened appropriately Chronic cases of what looks like PR lasting longer than the typical to weeks should be evaluated for pityriasis lichenoides Since the condition is self-limited and often asymptomatic, reassurance and anticipatory guidance may be sufficient For those who are symptomatic or desire a more rapid remission, treatment with oral acyclovir (ostensibly to treat HHV 6,7) or oral erythromycin (presumably for its anti-inflammatory properties) for 10 to 14 days may hasten resolution of the condition Pityriasis rubra pilaris PRP is a rare chronic inflammatory skin condition typified by salmoncolored, orange-red follicular papules and larger plaques accompanied by