An 89-year-old woman presented with plaque-like lesions, accompanied with pustules and desquamation on the back and front of the trunk for approximately one year. Long term use of potent topical corticosteroids was ineffective. Because of the chronicity of her condition, the diagnoses of subcorneal dermatosis or subcorneal pustular dermatosis type of IgA pemphigus were considered. However, fungal hyphae were observed in the potassium hydroxide examination. Therefore, we present this case since this clinical appearance of tinea incognito can also mimic various pustular dermatoses.