Last reviewed: January 2024
Author: Stanley Leong, Dermatology and Paediatric Registrar, November 2023
Reviewing dermatologist: Dr Ian Coulson (2024)
Edited by the DermNet content department
This 60-year-old man has previously had multiple squamous cell carcinomas (SCCs) of the scalp removed. He also had a history of infiltrative SCC requiring local radiotherapy to his scalp 8 years ago.
He recently developed multiple plaques with pus under the crusts on his vertex. The crusts were removed and revealed underlying superficial erosions. The ulcers had not healed after months.
The most likely diagnosis is erosive pustular dermatosis of the scalp.
It is more common in elderly men with a sun-damaged bald scalp, a history of actinic keratoses, and/or a history of SCCs or basal cell carcinomas (BCCs) of the scalp.
It is usually diagnosed by its characteristic clinical appearance.
Initially, a small area of the scalp becomes red, crusted, and irritated. Crusting and superficial pustulation usually overlies a moist, eroded surface.
Extensive disease can result in scarring and extensive alopecia.
SCC can develop in the scars.
Potent or ultrapotent topical steroids will suppress the inflammatory changes. Gradual reduction in the potency of topical steroid used over a 6-month period may result in cure. Failure to respond to this should prompt biopsy to exclude malignancy.
There is some evidence for using oral zinc sulfate, topical calcipotriol, and topical dapsone. Oral retinoids may also be tried.
Maintenance therapy with sun protection and intermittent moderate-potency topical steroids can provide long-term relief.
