Segmental lesions in pityriasis rosea: a rare presentation

A 34-year-old nonpregnant woman noted a mildly pruritic skin lesion on her right breast for 1 week following an episode of coryza, malaise, and low-grade fever of 3 days' duration. The latter symptoms subsided without any treatment. Ketoconazole cream prescribed by her family physician did not resolve the breast eruption after 1 week, so was stopped. A week later, multiple skin lesions erupted suddenly on her right chest wall starting near the herald patch in midaxillary line and spread distally until the midback. She then consulted the authors. She denied a history of abrasion or trauma to the affected areas. Travel, contact, sexual, and drug histories were unremarkable. She categorically denied past or family history of eczema, psoriasis, contact dermatitis, and drug eruptions. On examination, the initial lesion was an annular and well-demarcated erythematous plaque on her right breast in the upper outer quadrant. Multiple small oval scaly plaques were noted, extending distally along the ribs to the midline on her back, not crossing the midline, predominantly over the distribution of right T4 dermatome (Figure 1). Peripheral collarette scaling was noted (Figure 2). A few scattered small lesions were also noted in the vicinity of this dermatome. Three isolated small plaques were also present on the trunk, one in the supramammary area and the other two on the abdomen and back, respectively. Palmoplantar and mucosal surfaces were uninvolved. The rest of the skin and systemic examination revealed no abnormalities. Complete blood cell counts, fasting glucose, and urinalysis were normal. Venereal Disease Research Laboratory (VDRL) results were nonreactive and human immunodeficiency virus (HIV) antibodies were negative. Repeat testing ofVDRL in serial dilutions and HIV antibodies after 3 months were also nonreactive and negative, respectively. Scrapings from the initial large lesion and subsequent smaller eruptions did not show any evidence of fungal infection on potassium hydroxide smear examination. The patient declined skin biopsy; however, we thought that the most diagnostic label for this condition was pityriasis rosea. Hence, we treated her with triamcinolone acetonide ointment 0.025% to be applied twice daily and desloratadine tablet 5 mg daily for 10 days. The patient demonstrated complete resolution, leaving postinflammatory hypopigmentation. There was no recurrence until 1 year after complete remission.