AEGCG usually presents with annular, erythematous, photodistributed plaques with raised borders and atrophic centers. Plaques are usually asymptomatic and have been reported to appear suddenly and persist for varying durations, from months to years.
The pathophysiology of AEGCG is not fully understood. It has been hypothesized that solar radiation or heat alters elastin peptides and causes them to induce the formation of granulomata, which subsequently irreversibly destroy elastic fibers. While AEGCG is classified by some as a distinct entity, others view it as a variant presentation of granuloma annulare.
Case reports have described an association of AEGCG with underlying malignancies (acute myeloid leukemia, CD4 T-cell lymphoma, adult T-cell leukemia, and urothelial bladder carcinoma) as well as with other diseases (diabetes mellitus type 2, giant cell arteritis, and Hashimoto thyroiditis). It is unclear whether there is a causal, concomitant, or coincidental relationship between AEGCG and these diseases.
This entity is also known as "atypical annular necrobiosis lipoidica," "necrobiosis lipoidica presenting on the face and scalp," and "Miescher's granuloma of the face" in older literature.
Variants:
- Generalized variant – Annular plaques or papules involving both sun-exposed and covered areas. It has an indolent course with a gradual dissemination and enlargement of existing lesions with eruption of new lesions over time.
- Papular variant – Papular lesions instead of annular plaques.
