Annular Elastolytic Giant Cell Granuloma in a Post-COVID-19 Patient: A Case Report

Annular elastolytic giant cell granuloma (AEGCG) is a rare inflammatory skin condition characterized by the irreversible destruction of elastic fibers in the dermis, according to a case report published in Cureus and supporting data from explorer.cuni.cz. While typically associated with sun exposure, recent clinical documentation includes a case of the condition appearing in a patient following a COVID-19 infection.

The condition involves an autoinflammatory response where the body’s own immune system attacks elastin, the protein that allows skin to stretch. According to DermNet NZ, this process is thought to be a CD4-mediated response where macrophages and dendritic cells phagocytose elastin fragments, leading to the formation of multinucleated giant cells.

Clinical Presentation and Irreversible Skin Damage

A 67-year-old man presented with red papules that coalesced into well-demarcated plaques on his left thigh, axillae, and the lateral parts of the trunk, according to explorer.cuni.cz. The older lesions developed a frilled surface as they grew slowly over time.

Medical providers used a skin biopsy to confirm the diagnosis. The biopsy revealed a zone where elastic fibers had disappeared, surrounded by a rim of giant multinuclear cells containing fragments of those fibers, according to explorer.cuni.cz.

While corticosteroid therapy successfully resolved the active inflammation, the physical damage to the skin remained. A second biopsy taken 1.5 years after the initial remission confirmed the absence of elastic fibers at the site of the previous lesion, proving that the phagocytosis of the fibers was irreversible, according to explorer.cuni.cz.

Causes and Risk Factors for AEGCG

AEGCG, also known as actinic granuloma or O’Brien granuloma, most commonly affects individuals between the ages of 40 and 70, according to DermNet NZ. It typically appears on sun-exposed areas such as the face, neck, and dorsal hands, though it can occur in non-sun-exposed regions.

The development of the condition is linked to several environmental and host factors, according to DermNet NZ:

• Environmental triggers: Solar radiation and heat.
• Common comorbidities: Diabetes mellitus is the most frequent associated condition.
• Autoimmune links: Vitiligo, Hashimoto’s thyroiditis, and autoimmune hepatitis.
• Other associations: Hypertension, hyperlipidaemia, Lyme disease (Borrelia burgdorferi), and certain malignancies, including leukaemia, lymphoma, and prostate adenocarcinoma.

DermNet NZ notes that human matrix metalloproteinase-12 (MMP-12), produced by macrophages, contributes to the breakdown of elastin. Upregulation of this enzyme in biopsy samples suggests it plays a role in the elastolysis process.

The most common form of the condition presents as annular, or ring-shaped, plaques with an elevated scaly border and central hypopigmentation, according to DermNet NZ. These lesions typically range from 1 to 10 cm in diameter and are generally asymptomatic, though some patients report burning or pruritus.

DermNet NZ identifies four other clinical subtypes beyond the annular form:

• Papular form: Groups of firm, non-scaly papules measuring 2 to 12 mm.
• Giant form: Oedematous, non-scaly plaques larger than 10 cm, usually found on the trunk.
• Generalised form: Lesions covering more than 30% of the total body surface area.
• Mixed form: The coexistence of two or more of the above subtypes.

Medical literature indicates that AEGCG is reported more frequently in people with lighter skin, though data on how the condition impacts varying skin types remains limited, according to DermNet NZ.