Progressive Macular Hypomelanosis Arising in a Young African American Woman inAssociation With Pregnancy and a Toxic Nodular Goiter

The authors present the case of a 23-year-old woman of French-Caribbean descent who presented with progression of hypopigmented, scaly ovoid macules on her neck, chest, abdomen and back. She was two months pregnant at the time of the onset of the pigmentary change was also simultaneously diagnosed with a toxic nodular goiter of her thyroid gland. Initial fungal culture, KOH and biopsy were positive for fungal hyphae, and she was treated with four weeks of oral ketaconazole and topical selenium sulfide shampoo. As she had continued progression of her hypopigmented lesions after treatment for pityriasis versicolor, a thorough physical examination (under room light and Wood’s lamp) and repeat biopsy were performed. On examination, she demonstrated persistence of the ovoid hypopigmented macules on her neck, chest and abdomen with interval improvement of the superficial scaling. Under Wood’s lamp examination, hypopigmented lesions demonstrated a characteristic follicular pink fluorescence associated with porphyrin production by Propionobacterium acnes (P. acnes) described previously in the lesions of progressive macular hypomelanosis (PMH). PMH was confirmed histologically by the findings in the second biopsy of a decrease in epidermal melanin pigment and the persistence of pityriasis versicolor was ruled out by an absence of fungal hyphae. Based upon the literature suggesting improvement of PMH with antibiotic therapy to decrease P. acnes colonization, she was treated with 10% benzoyl peroxide wash, clindamycin 1% solution and oral, twice-daily tetracycline 500 mg. During six months of this treatment, she experienced re-pigmentation of many of her existing skin lesions and cessation of the development of new hypopigmented macules.