Hyperkeratotic plaque in axilla mimicking acanthosis nigricans

Sir, a 42-year-old woman from rural area presented with an asymptomatic rash involving both axillae for 2 months. she admitted to strict avoidance of washing this area with soap and water, initially because of cold weather and later on, because of burning sensation associated with attempts at cleaning the affected areas. physical examination revealed well-defined hyperpigmented hyperkeratotic plaques in both axillae, mimicking acanthosis nigricans (figure 1).