-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