Makindo Medical Notes

Granuloma annulare is harmless, does not affect general health, is not infectious or contagious, and is not due to allergies. Some types of granuloma annulare have been linked with diabetes, though the exact cause is often unknown.

About

• Affects people of all ages, though more common in children and young adults.
• Typically presents as localized (most common) or generalized forms.
• Localized rash usually found on hands and feet. A generalized form can spread to larger body areas.

Aetiology

• Type IV hypersensitivity reaction. T-cell mediated immune response against antigens in the dermis.
• Associations with diabetes mellitus, thyroid disease, and occasionally malignancy.
• Other triggers may include trauma, infections, or sun exposure.

Clinical Features

• Typically non-itchy, circular, raised lesions that have a smooth surface.
• Common sites include the elbows, extensor aspects of the forearms, hands, and knuckles.
• Lesions range from skin-colored to violaceous (purplish) and may reach up to 5 cm in diameter.
• In generalized cases, multiple lesions may appear on the trunk and limbs.

Investigations

• Blood glucose testing to rule out diabetes.
• Skin biopsy can be performed in atypical cases - differential is tinea corporis.

Management

• Usually self-limiting and resolves on its own within months to 2 years.
• Topical treatments:
  • Topical corticosteroids to reduce inflammation in localized cases.
  • Intralesional steroid injections for stubborn lesions.
• Generalized granuloma annulare may be treated with systemic therapies, such as:
  • Oral corticosteroids in severe cases.
  • Phototherapy (PUVA) or UVB light therapy.
  • Hydroxychloroquine or dapsone may be prescribed in resistant cases.
• Patient education:
  • Reassure the patient that the condition is benign and non-infectious.
  • Regular follow-ups may be necessary, especially in cases associated with underlying systemic conditions like diabetes.

References

• Smith, J. A., & Brown, L. (2019). *Granuloma Annulare: Diagnosis and Management*. Dermatology Journal.
• Jones, R. D. (2020). *Skin Disorders and Diabetes Mellitus*. Journal of Endocrinology.
• American Academy of Dermatology - Granuloma Annulare