Uncommon Petaloid Form of Seborrheic Dermatitis Seen in Fitzpatrick Skin Types V-VI

Seborrheic dermatitis (SD) is an inflammatory disease that has a papulosquamous morphology in areas rich in sebaceous glands such as the scalp, face, and body folds. Petaloid SD is an uncommon presentation found in patients with dark skin (Fitzpatrick Skin type V-VI). This form of SD can appear as pink or hypopigmented polycyclic coalescing rings or scaly macules and patches in the typical areas SD appears, which can mimic other conditions including lupus erythematosus. There is significant disproportion in the representation of darker skin types in dermatological textbooks and scarce literature on petaloid SD. This case demonstrates the presentation of the petaloid SD in an African American patient to contribute to the limited literature on dermatological conditions within this population.

A 25-year-old African American female with a history of mild hidradenitis suppurativa and asthma who presented with asymptomatic hypopigmented rashes throughout her face, scalp, and chest. She was diagnosed with the petaloid form SD and treated with ketoconazole shampoo once weekly, ketoconazole cream 1-2x daily, and hydrocortisone 2.5% ointment twice daily as needed. At six-week post-treatment follow-up, the patient's rashes significantly improved.

The petaloid form of SD is commonly experienced in dark-skinned patients. While common treatments for SD are effective in this form of SD, special consideration of skin types, skincare habits, and haircare in the African American population should be explored. This case report demonstrates how this uncommon skin condition presents in patients of Fitzpatrick skin type V-VI and a successful treatment course.