What is Flegel disease?
Flegel disease is also known as hyperkeratosis lenticularis perstans. It was first described by Flegel in 1958. It is characterised by red-brown papules with irregular horny scales located mainly on the top surface of the feet and lower legs. It is very similar to Kyrle disease and has been regarded as a variant of Kyrle disease, however its clinical and pathological picture is sufficiently different to make it its own disease entity.
What causes Flegel disease?
The cause of the disease is unknown. It is thought to be an inherited condition although cases have been reported where there is no family history of the disease. Exposure to the sun has also been implicated but not proven.
Flegel disease has been reported to rarely affect some families that were also prone to skin and gastrointestinal cancers.
What are the clinical features of Flegel disease?
Lesions are small, red-brown, 1–5 mm scaly papules that appear most commonly on the top surface of the feet and lower legs. Removal of the scale reveals a bright red base, often with pinpoint bleeding. In rare instances, the outer ear lobes, arms, palms, soles, and oral mucosa may be affected. The papules are not usually painful.
Flegel disease
How is Flegel disease diagnosed?
Flegel disease is sometimes diagnosed clinically, especially if there is a family history of Flegel disease. Otherwise, a biopsy may lead to a pathological diagnosis of Flegel disease.
What treatment is available?
Lesions are benign and are mainly treated for cosmetic reasons. Treatment of Flegel disease includes:
- Topical 5% fluorouracil cream used over several months
- Dermabrasion
- Cryotherapy
- Topical retinoid
- An oral retinoid such as acitretin or isotretinoin.