Annular lichenoid dermatitis of youth
The condition was described initially in children and young adults. The median age of onset is approximately 10 years. However, cases of annular lichenoid dermatitis have also been described in adult patients, and the disease has been seen in patients ranging from 1-45 years of age. Male and female patients are equally affected. While most cases described are from Mediterranean countries, several cases from the United States, Japan, and Europe have also been reported.
Only approximately 50 cases of ALDY have been reported in the literature. However, it is unclear if the prevalence of ALDY is low or if the condition is underreported.
While the etiology of ALDY is still undetermined, several case reports have suggested a possible association with Borrelia infection, hepatitis B vaccination, and contact dermatitis. Immunohistochemical studies demonstrate a T-cell mediated immune reaction, similar to other lichenoid diseases.
L30.8 – Other specified dermatitis
12873001 – Lichenoid dermatitis
Differential Diagnosis & Pitfalls
- Morphea – Active morphea may have an annular erythematous violaceous border. The center is indurated and may be atrophic.
- Patch-stage mycosis fungoides
- Purpura annularis telangiectodes (of Majocchi; annular form of benign pigmented purpura)
- Secondary syphilis
- Erythema annulare centrifugum
- Erythema migrans
- Urticaria multiforme
- Tinea corporis – typically scaly
- Annular erythema of Sjögren syndrome
- Eosinophilic annular erythema
- Borderline leprosy