Granuloma Annulare

Granuloma Annulare 

Granuloma annulare (GA) is a chronic, usually self-limited, inflammatory disorder of the dermis that classically presents as arciform to annular plaques located on the extremities.

Synonyms

  • Pseudorheumatoid nodule—subcutaneous granuloma annulare
  • GA

Epidemiology & Demographics

  • •Most common in children and young adults; most cases of localized GA are diagnosed in patients <30 yr
  • •Female predominance (2:1)
  • •Disseminated form associated with diabetes mellitus
  • •Recurrent in 40% of affected individuals
  • •A generalized form of GA can occur in up to 15% of patients

Physical Findings & Clinical Presentation

  • •The main clinical variants of GA are localized (75%), disseminated (>10 lesions), subcutaneous (occurring primarily in children ages 2 to 5 yr), patch-type or macular GA, and perforating (rare form manifesting with 1- to 4-mm papules with a central crust usually appearing on the dorsal hands).
  • •Localized GA starts as a small ring of colored skin or pale erythematous papules. More common in children and young to middle-age adults. Usually, only one or a few lesions occur at any one time.
  • •Lesions coalesce and evolve into annular plaques over several wk.
  • •Plaques undergo central involution and increase in diameter over several mo (0.5 to 5 cm).
  • •Most frequently found on the lateral and dorsal surfaces of the hands and feet.
  • •Most lesions resolve spontaneously after several mo.
  • •The generalized form of GA is characterized by hundreds of small (lesions rarely exceed 5 cm in diameter), flesh-colored papules in a symmetric distribution on the trunk and extremities. It most commonly affects women in the fifth or sixth decades but can also be seen in adolescents and children. Some patients are completely asymptomatic, whereas others complain of severe pruritus.
  • •Macular GA is more common in women between ages 30 to 70 yr and manifests with flat or slightly palpable erythematous or red-brown lesions on upper medial thighs and in bathing-trunk distribution.
  • •Deep dermal GA (subcutaneous GA) presents as large, painless, skin-colored nodules that are frequently mistaken for rheumatoid nodules.

What causes Granuloma Annulare?

Unknown, but may be related to vasculitis, trauma, monocyte activation, or delayed hypersensitivity.

How is Granuloma Annulare diagnosed?

Differential Diagnosis

  • •Tinea corporis
  • •Lichen planus
  • •Necrobiosis lipoidica diabeticorum
  • •Sarcoidosis
  • •Rheumatoid nodules
  • •Late secondary or tertiary syphilis
  • •Arcuate and annular plaques of mycosis fungoides
  • •Papular GA can simulate insect bites, secondary syphilis, xanthoma
  • •Annular elastolytic giant cell granuloma

Workup

  • •Diagnosis based on clinical appearance and presentation
  • •Biopsy when diagnosis is unclear

Laboratory Tests

  • •Laboratory tests will not help confirm the diagnosis.
  • •Biopsy shows focal degeneration of collagen and elastic fibers, mucin deposition, and perivascular and interstitial lymphohistiocytic infiltrate in the upper and middle dermis.

How is Granuloma Annulare treated?

Nonpharmacologic Therapy

Reassurance, given the self-limited and benign nature of GA

Chronic Treatment

High-potency topical corticosteroids (with or without occlusion) and intralesional steroid injection into elevated border with triamcinolone 2.5 to 10 mg/ml are useful first-line local therapies.

  • •Cryosurgery, psoralen ultraviolet-A (UVA) range or UVA-1 therapy, and carbon dioxide laser treatment can also be used.
  • •Systemic agents (e.g., niacinamide, hydroxychloroquine, chloroquine, cyclosporine, dapsone) are generally reserved for severe cases. Recent case reports indicate positive outcomes with tacrolimus and pimecrolimus and the tumor necrosis factor infliximab.

Disposition

Most lesions resolve spontaneously within 2 yr.

Referral

Dermatology referral recommended for symptomatic, disseminated disease.

Pearls & Considerations

GA has been described as a paraneoplastic granulomatous reaction to Hodgkin disease, non-Hodgkin lymphoma, solid organ tumors, and mycosis fungoides.

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