- In addition to the axilla, may be seen in other intertriginous sites and occasionally elsewhere
- Unknown etiology. There is a defect in the processing of profilaggrin to filaggrin, resulting in a failure to degrade keratohyaline granules.
- Controversial association with with the use of deodorant
- Red to hyperpigmented patches that may clinically resemble acanthosis nigricans
- Thick parakeratotic stratum corneum which retains the keratohyaline granules
- The underlying epidermis may be normal, mildly atrophic or show psoriasiform hyperplasia.