Granuloma Annulare (GA)

Definition

Granuloma annulare (GA) is a chronic dermatological condition presenting as smooth, discoloured annular plaques or papules. Lesions can have a “string of pearls” appearance with raised borders and central clearing. Although it can occur at any age, GA commonly affects children and young adults, often on the hands and feet.

Types & Associations

• Localised GA

  • Tends to be limited to a few discrete areas (e.g., backs of hands, feet).

  • Can be linked to autoimmune thyroiditis, though treating thyroid disease doesn’t always resolve GA.

• Generalised (Disseminated) GA

  • More extensive involvement, potentially widespread.

  • Associated with diabetes, hyperlipidaemia, and in rare cases, HIV, lymphoma, or solid tumours.

  • Typically warrants further evaluation if abrupt or extensive onset.

Clinical Features

• Commonly affects hands and feet, though can appear on other body areas.

• Lesions are often asymptomatic, though some patients report mild tenderness if the lesion is bumped or scraped.

• Characteristic ring-shaped plaques: Central area may appear slightly depressed or normal in colour, with a raised, annular border.

Differential Diagnosis

• Tinea manuum: Fungal infection of the hands, typically has scale, pruritus, and a possible active leading edge.

• Pompholyx (dyshidrotic eczema) or contact dermatitis: Generally more vesicular or intensely pruritic, with a different distribution pattern.

• Palmoplantar psoriasis: Usually well-demarcated plaques with scaling, possible nail changes.

Management

• Self-Resolving

  • Many cases resolve spontaneously over months to a few years, without scarring.

  • Reassure patients if lesions are not bothersome.

• Local Therapies (for persistent or unsightly lesions):

  • Topical corticosteroids under occlusion (e.g. betamethasone dipropionate 0.05% BD for up to 4 weeks)

  • Intralesional steroid injections for isolated plaques

  • Cryotherapy or laser ablation (less commonly used, typically for resistant or cosmetically significant lesions)

• When to Treat:

  • If lesions are unsightly, painful, or interfere with daily life (e.g. friction over joints)

  • If no resolution in several months or uncertain diagnosis, consider skin biopsy to confirm and exclude other causes.

Notes

• While GA may be associated with underlying conditions (e.g. thyroid disease, diabetes, dyslipidaemia), many patients have idiopathic disease.

• Checking fasting glucose or HbA1c and lipids may be considered if GA is widespread or recurrent, given some link with metabolic disturbances.

• Recurrences can happen even after lesions resolve.