A 39-year-old woman presented for diagnosis and management of a rash failing treatment in primary care. Over the preceding 18 months, our patient had experienced a mildly itchy flexural and upper back reticulate pigmentation. The primary care physician made a correct clinical diagnosis of pityriasis versicolor. Subsequent topical twice-daily application of miconazole cream and a 7-day regimen of daily oral itraconazole, 200 mg, failed to clear the rash.
In the dermatology clinic, further questioning revealed unusual cravings for soap. She was consuming formed soap up to 5 times a day, including while taking antibiotics. Subsequent iron level studies confirmed low serum iron concentration, low iron saturation, and low ferritin levels with an elevated iron-binding capacity. Pregnancy test results were negative. A repeated 14-day course of itraconazole with iron replacement and soap avoidance was instituted with success.
Tallon BG, Oliver GF. Where Pityriasis Versicolor and Pica Collide. Arch Dermatol. 2008;144(6):813-814. doi:10.1001/archderm.144.6.813