No hypopigmented lesion, no nerve thickening, but its leprosy!

Sir,

Ulcerative erythema nodosum leprosum is rare presentation of erythema nodosum leprosum (ENL). At times, patient may present to the physician with lesions of ulcerative ENL alone without any other sign of leprosy. Such cases may pose diagnostic difficulty to the treating physician. Here we are describing one such case.

A 23-year-old woman presented us with complaints of painful lesions over both hands and legs of 3 months duration. Lesions were small, pus filled initially, that gradually enlarged and eroded to form ulcers followed by fresh pustules all over. On dermatological examination, multiple pustules and ulcers of varying sizes and shapes with dark violaceous border were scattered mainly over the lower limb. Other sites of involvement were upper limb and face [Figures 1 and 2].

Figure 1

Ulcers over the leg with violaceous border mimicking ulcerative type of pyoderma gangrenosum

Figure 2

Pustular and ulcerative lesions present over the face and hands

At this point of time, we considered the provisional diagnosis of ulcerative type of pyoderma gangrenosum. As pyoderma gangrenosum is a diagnosis of exclusion, we wanted to rule out other differential diagnosis also. History of high risk behavior was present in spouse. The patient was giving treatment history with long term antibiotics without any improvement. So the possibility of pyoderma with underlying retro viral infection was also considered. The patient was put on broad spectrum antibiotics. Enzyme linked immunosorbent assay (ELISA) was done for human immunodeficiency virus (HIV), but the report came negative. Patient was not improving clinically. Slit skin smear was done and results were positive [Figure 3]. The patient was re-examined for the presence of hypopigmented lesions and nerve thickening, but both were not present. There was no sensory loss or deformity. Biopsy was done and reports were consistent with vasculitis of ENL.

Figure 3

Slit skin smear showing multiple acid fast bacilli (Giemsa stain, ×1000)

The patient was started Multi Drug Therapy along with systemic steroids. Daily cleansing the ulcers with Condy's solution was done. The condition of the patient improved drastically and skin ulcer healed completely in few days.

A person with leprosy is defined as an individual who has not completed a course of treatment for leprosy and has one or more of the following cardinal signs:[12]

Hypopigmented or erythematous skin lesion with loss of sensation.

Involvement of peripheral nerves as demonstrated by thickening of nerves and loss of sensation over the area supplied.

Skin smear positive for acid fast bacilli.

Skin smear is one of the separate cardinal signs of leprosy.[3] Sensitivity of skin smear is rarely more than 50% because smear positive patients are 10-50% of all cases, but the specificity of the test is 100%.[23] It may be of prime use when leprosy is suspected even in absence of hypopigmented lesions or nerve thickening as in our patient.

To conclude, authors would like to say “Leprosy is a great mimicker. The diagnosis may be missed unless thought of.”