Atypical erythema nodosum leprosum as the presenting feature in multibacillary leprosy: a case report.

Sir,

Leprosy can rarely present with erythema nodosum leprosum (ENL). Type 2 reaction or ENL is characterized by brightly red, raised, evanescent, tender nodules, and plaques of varying sizes. Extracutaneous manifestations include fever, neuritis, arthritis, epididymo-orchitis, iridocyclitis, epistaxis, etc., and rarely, glomerulonephritis. Atypical presentations may occur, though rarely.

A 36-year-old male presented with progressive nodular, ulcerative and impetiginous lesions over trunk, upper extremities and thighs for 3 months [Figure 1]. Disease started as small tender nodular lesions over trunk and gradually spread over both upper and lower limbs. The nodules turned into vesicles, which ruptured leaving behind crusted lesions some showing distinct peripheral collar. Few lesions were ulcerated. There was also history of fever and joint pain. He had no history of sensory disturbances or weakness or numbness of any part at that time. There was no definite anesthetic patch. Peripheral nerves were not thickened. Local lymph nodes were not enlarged.

Figure 1

Impetiginous crusted lesions on the upper limb

Complete hemogram and ESR were normal. Bacterial culture of the pus revealed no growth of organism.

Histopathological examination revealed a narrow grenz zone separating flattened epidermis above and dense inflammatory cells in dermis comprising of sheets of foam cells admixed with polymorphs, lymphocytes, and histiocytes [Figure 2]. Fite stain showed numerous solid and fragmented acid fast bacilli discretely as well as in clusters [Figure 3].

Figure 2

Histopathology showing dermis with grenz zone and foam cells (H and E, ×10)

Figure 3

Histopathology of lesional biopsy demonstrating foam cells and both intact and fragmented bacilli (Fite Faraco stain)

The patient was diagnosed to have lepromatous leprosy with type 2 reaction and treated with standard multidrug therapy (MDT) and 1 mg/kg of oral prednisolone.

ENL is characterized by development of recurrent painful nodules along with other constitutional symptoms in the background of borderline lepromatous or lepromatous leprosy. Important organs such as peripheral nerves, eye, and testes may be involved. ENL mostly occurs during the first 6 month of treatment with MDT, but may also develop after completion of treatment.[1] Exacerbating factors such as stress, pregnancy, lactation, concurrent illness, vaccination, and medication have been identified.[2] The bacteriological index usually remains high in ENL. In earlier studies, it has been observed that ENL is more common when the morphological index is less than 5.[3] It is a Coomb and Gell Type III hypersensitivity reaction. In ENL, release of bacillary antigen leads to immune complex deposition which triggers a vasculitic process resulting in release of TNF-α and subsequently an inflammatory episode.

Besides typical ENL lesions, some atypical variants also have been reported. Bullous variety needing I.V. hydrocortisone for control has been recorded.[4] Switching from Rifampicin in the conventional MDT to the highly bactericidal drug Ofloxacin gave rise to a pustular variety of ENL.[5] A case of ENL with severe skin ulcerations from Bangalore had to be treated with oral thalidomide in addition to oral prednisolone.[6] Our case was not unlike this case. It has responded favorably to oral prednisolone in addition to supportive management though complete resolution has not been achieved yet. Such persistent lesions can give rise to distressing chronic painful panniculitis.[6] Sweet syndrome like presentation has been reported by Kou and Chan[7] This later case responded to high dose systemic corticosteroids. Unusual forms of ENL continue to pose problems for the clinician and there are many varieties. Our case presented with painful nodular lesions which subsequently turned into vesicles which ruptured leading to ulcers and impetiginous crust. We report this case to draw attention to an uncommon presentation of leprosy in the form of ENL with polymorphic presentation in the same patient.