A Rare Report of Granuloma Multiforme.

Sir,

The term granuloma multiforme was coined in 1964 by Leiker et al., to describe a reactive skin disorder of unknown etiology “resembling leprosy” with “the variety of clinical presentation and the granulomatous histology.”[1] Characterized clinically by confluent annular lesions and histopathologically by focal necrobiosis and histiocytic granulomas, most of its cases have been found mistakenly receiving treatment for leprosy in leprosy settlements from the African continent.[2] Our present report is probably, the fifth from India[2345] and the first from Maharashtra.

A 59-year-old housewife presented with numerous annular plaques over forearms, which commenced as itchy papules 3 years back and gradually extended to involve upper back. There were neither any seasonal and diurnal variations nor any aggravating or relieving factors. Denied history of contact with known patients of leprosy. Her body mass index was 33. Dermatological examination revealed numerous erythematous, clustered papules symmetrically over hands, forearms [Figure 1], upper back forming well-defined, and polycyclic plaques with central clearing without any sensory loss or peripheral nerve thickening. Biopsy from the edge of a lesion on left forearm revealed mid-dermal lymphohistiocytic infiltrate with many multinucleated giant cells surrounding foci of necrobiotic collagen [Figure 2], and perivascular lymphocytic infiltrate [Figure 3]. The colloidal iron stain did not reveal increased mucin deposition, which ruled out granuloma annulare. Ziehl–Neelsen stain did not reveal acid-fast Bacilli. These classical clinical and histopathological findings corroborated the diagnosis of granuloma multiforme. Complete hemogram, urinalysis, kidney and liver function tests, blood glucose levels, and T3, T4, thyroid stimulating hormone were normal. A trial of topical corticosteroids failed to show any improvement.

Figure 1

Polycyclic plaques with central clearing over ventral aspect of forearm

Figure 2

Dermis showing necrobiotic granuloma (H and E, ×100)

Figure 3

Dermis showing prominent multinucleated giant cells with perivascular lymphohistiocytic infiltrate (H and E, ×400)

Cumulative photodamage to the dermal collagen has been favored as the primary pathogenetic event of granuloma multiforme, whose lesions in almost all cases have been confined to sun-exposed sites.[2] Some believe, this disorder to be granuloma annulare on light-exposed areas because of relatively similar clinical and histological features. Adults over 40 years, more so females, are commonly affected.[3] Pruritus and irritation are especially associated with the onset of small papules of granuloma multiforme; these papules aggregate to form annular and polycyclic patterns extending peripherally with central clearing, usually with residual hypopigmentation and occasionally hyperpigmentation. Response to the treatment is poor.

Granuloma annulare, actinic granuloma, sarcoidosis, and necrobiosis lipoidica diabeticorum also need to be considered in the differential diagnosis of granuloma multiforme in addition to the usual mimic of tuberculoid leprosy;[2] the latter having sensory impairment, nerve trunk thickening but lacking degenerated collagen.[4] Granuloma annulare presents with asymptomatic lesions in younger age group and reveals increased mucin deposition surrounded by granulomatous zone histopathologically with scarce giant cells with fewer nuclei.[2] The yellowish color of the plaques, telangiectasia, the involvement of the lower limbs, and the presence of fibrosis intermingled with necrosis, vessel wall changes and fat deposition in deep reticular dermis characterize the necrobiosis lipoidica.[4]

Extremely few reports of granuloma multiforme from India, despite foci of endemic leprosy, indicate possible misdiagnosis and emphasizes the need for heightening index of suspicion for this condition in the differential diagnosis of annular granulomatous disorders. Corroboration by lesional histopathological examination usually suffices to clinch the diagnosis.

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