-IBIS-1.5.0-
tx
cutaneous system
pityriasis rosea
diagnoses

definition and etiology

definition: a mild idiopathic inflammatory scaling skin disease

etiology: cause is unknown; although an infectious agent has not yet been confirmed, it is a likely factor; seen mainly in children and young adults

signs and symptoms

signs and symptoms:
• "herald" or "mother" patch typically appears on the trunk, but may be anywhere other than the face; noticed 3-14 days before the generalized eruption; circular, 2-6 cm in diameter, brownish-red or rose colored, with a scaly, raised border
• generalized eruption appears 3-14 days after the herald patch
• lesions are similar in appearance to herald patch lesion, but smaller (0.5-2 cm in diameter).
• appear on trunk and extremities; on the back, may appear in a "Christmas tree" pattern radiating out from the spinal column
• bran-like scales are found on the periphery of the lesions
• new lesions continue to erupt for 2- 3 weeks
• mild itching may be found in 15% of patients
• some patients will have headache and generalized symptoms

lab findings:
• serologic testing for secondary syphilis should be performed

course and prognosis

Prognosis is excellent; the disease is self-limiting in 4-12 weeks, and recurrences are rare. Conventional treatment neither exists nor is needed. Phototherapy with UV may speed resolution.

differential diagnosis

• drug eruption
• dermatitis
• secondary syphilis
• tinea corporis
• tinea versicolor
• tinea pedis
• psoriasis


footnotes