Recurrent ulcers: a diagnostic challenge.

Sir,

A 37-year-old lady presented to our out patient department with a history of low-grade fever and multiple painful erythematous nodules on the body, predominantly distributed on the extremities of 2 months duration. Within 3 days, they progressed to form deep punched out ulcers [Figure 1]. She was also found to have atrophic rhinitis. She gave no history of photosensitivity, malar rash, morning stiffness, or trauma. She has no history of any drug intake prior to the appearance of the lesions. She had no motor or sensory deficits.

Figure 1

Necrotic punched ulcers

Based on the clinical findings, the initial differential diagnoses considered included Pyoderma gangrenosum, Wegeners granulomatosis, and nodular vasculitis. On investigating the patient, she was found to have leukocytosis with a total count of 15000/cumm. The other routine laboratory investigations, Mantoux intradermal test, autoantibody screening, viral and serological analysis, blood culture, and swabs for bacteria were unremarkable.

Histopathology of the skin revealed a large intradermal cleft filled with fibrin and a few inflammatory cells. The epidermis overlying the cleft has orthokeratosis, parakeratosis, hypergranulosis, and acanthosis. The dermis showed dilated vessels with endothelial cells and fibrinoid degeneration of the vessel wall surrounded by neutrophilic dust. A dense granulomatous infiltrate with lymphocytes and macrophages was found around the vessel walls [Figure 2a]. Septal and lobular panniculitis was present [Figure 2b]. Taking the clinical picture into consideration, a diagnosis of nodular vasculitis was made, and treatment was instituted for the same with oral steroids and dapsone. But, despite institution of therapy, the response to treatment was unsatisfactory.

Figure 2a

Histopathology of the skin showing dilated vessels with prominent endothelial cells, fibrinoid degeneration of the vessel wall, perivascular lymphocytic infiltrate and macrophages and septal panniculitis (H and E, ×40)

Figure 2b

Histopathology of the skin showing dilated vessels with prominent endothelial cells, perivascular lymphocytic infiltrate and macrophages and septal panniculitis (H and E, ×40)

The patient was re-evaluated. The clinical examination revealed minimal ear lobe infiltration and thickened peripheral nerves. A repeat biopsy was done and stained with Fite Faraco, which showed clumps of beaded and fragmented acid-fast bacilli. Slit skin smears were 3.75+ [Figure 3]. On the basis of these findings, she was diagnosed to have lepromatous leprosy with nodulo-ulcerative erythema nodosum leprosum (ENL). She was started on oral prednisolone 40 mg tapered by 5 mg every 2 weeks, oral thalidomide 100 mg thrice-daily, and multidrug therapy for multibacillary cases as recommended by the World health organization (WHO MBMDT). Her lesions responded well to therapy. Thalidomide was gradually tapered over the next 3 months to 50 mg/day and then discontinued.

Figure 3

A repeat biopsy stained with Fite Faraco stain showing clumps of beaded and fragmented AFB (×100)

We report this case because of the diagnostic dilemma posed in correctly identifying the cause of this patient's myriad symptoms. ENL is an immune complex-mediated reaction that may complicate the course of multibacillary leprosy.[1] It usually starts during the first 6 months of anti-mycobacterial treatment; however, it may continue to occur even after treatment. It commonly presents with multiple erythematous tender nodules with or without constitutional symptoms.[2] Erythema multiforme-like, vesiculobullous, pustular, ulcerated, and hemorrhagic lesions have been reported in ENL.[3] Necrotic lesions represent severe forms of reaction.

ENL as the first manifestation of leprosy is uncommon. In a study by Nery et al., only 11% of the patients presented de novo with lepra reactions, of which 5% had reversal reactions and 6% had ENL.[4] At the first visit, our patient presented with nodulo-ulcerative as her only finding with very mild systemic symptoms. ENL was not considered as an initial DD as the very subtle signs of leprosy were missed at the initial visit. In such cases, the clinician may not suspect leprosy and its reactions and may neglect a complete neurological examination, leading to a delay in diagnosis. This case report highlights the importance of a thorough clinical examination in such a situation and re-emphasizes the importance of looking for signs and symptoms of leprosy in this well-known but relatively uncommon entity.[5]

In conclusion, regardless of whether other symptoms or signs of leprosy are present, a diagnosis of ENL should be considered in any patient from leprosy endemic areas with acute, tender, erythematous nodules that may show necrotic ulceration. This case is just a reminder, lest we forget to include leprosy, the age old ‘great imitator’ as a differential diagnosis in our day-to-day practice.