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Erythema nodosum leprosum: A presenting manifestation of lepromatous leprosy

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Erythema nodosum leprosum: A presenting manifestation of lepromatous leprosy
Vandana Mehta MD DNB, C Balachandran MD
Dermatology Online Journal 12 (7): 29

Deptartment of Skin and STD, Kasturba Medical College, Manipal, Karnataka, India.

Lepromatous leprosy usually presents with multiple hypopigmented macules, papules, nodules, or plaques symmetrically distributed over the face, trunk, and extremities. Sometimes the presentation is unusual with a single nodule, spontaneous ulceration, histoid or lucio leprosy. We report an otherwise healthy and normal looking patient with no signs of cutaneous infiltration presenting with erythema nodosum leprosum (ENL) and with involvement of penile and scrotal skin.

Clinical synopsis

Figure 1 Figure 2
Figure 1. Close view of the patient
Figure 2. ENL lesions on the arm

Figure 3 Figure 4
Figure 3. Penile nodules
Figure 4. Ichthyosis on the legs

Figure 5 Figure 6
Figure 5. Absence of earlobe infiltration
Figure 6. Absence of madarosis

A 32-year-old man presented with erythematous nodules on the upper extremities and external genitalia of 4-days duration. The nodules were tender and evanescent. There was no history of any constitutional symptoms such as fever or joint pains, and no evidence of iritis, conjunctivitis, neuritis, or orchitis. He gave a history of tender nodular lesions over extremities in the past, each lasting for 2 weeks and subsiding with a course of NSAIDs and steroids. There was no history nor clinical evidence of hypopigmented, hypoanesthetic skin lesions, motor weakness, or glove-and-stocking anesthesia. Cutaneous examination revealed 1-2 cm, firm, tender, erythematous, subcutaneous nodules on the extensor aspect of upper arms. Nodular lesions were present on the scrotum and penis. Ichthyotic changes were present on the lower limbs. There was no madarosis or ear lobe infiltration. All the peripheral nerves were grossly thickened; sensory and motor examination was normal. Slit-skin smear for acid-fast bacilli from the nodules revealed a BI of 4+ and MI of 2 percent and from the scrotal skin showed BI of 2+ and MI 0 percent. All the hematological and biochemical investigation were within normal limits except a raised ESR. A biopsy from the erythematous nodule on the arm showed features consistent with ENL. The patient was started on WHO MB-MDT along with systemic steroids with which the nodules subsided in a period of 15 days.

Erythema nodosum leprosum is characterized by crops of tender erythematous subcutaneous nodules that appear bilaterally symmetrically on face and extremities in patients of lepromatous leprosy or borderline lepromatous leprosy. About 50 percent of lepromatous leprosy and 25 percent of borderline lepromatous leprosy patients experience an ENL reaction. The reaction is not always related to therapy and seems to be a manifestation of the disease. Precipitating factors for ENL including surgery, pregnancy, parturition, lactation, menstruation, trauma, intercurrent infection, vaccination, physical stress, mental stress, and multidrug therapy [1].

Lepromatous leprosy is known to cause widespread involvement of the skin attributed to hematogenous dissemination of the organisms. However it is known that Mycobacterium leprae has a district predilection for the cooler areas of the body and that the warmer areas such as groin, perineum, scalp, axilla, and the narrow zone of lumbosacral area are relatively spared and are considered to be immune zones in leprosy [2]. The presence of clinical lesions in the so called immune sites has been reported earlier by a number of workers [3]. It has been said that scrotal skin appears to be uninvolved clinically, even in patients with advanced lepromatous leprosy; our case, in fact, presented with nodular lesions on the scrotum. This could be explained by the liberal cutaneous innervation of the scrotum [4].

Histologically, scrotal skin is next to nerves in smear positivity, but in terms of bacterial load, it is preceded by nerves, lymph nodes, and nasal mucosa. Isolation rate of acid fast bacilli on biopsy from scrotal skin is also higher towards lepromatous spectrum [5].

This report further highlights the need for a thorough genital examination in all leprosy patients where early institution of anti-leprosy therapy and control of reactional episodes may decrease the subsequent complications of impotence and sterility.


1. Rea TH, Levan NE. Erythema nodosum leprosum in a general hospital. Arch Dermatol 1975 ; 111 : 1575.

2. Anish SA. The relationship between surface temperature and dermal invasion in lepromatosis leprosy. Int J Lepr 1971 ; 39 : 848 - 857.

3. Parikh AC, D'souza NG, Chulawala R. Leprosy lesions in scalp. Lepr India 1974 ; 46 : 39.

4. Murphy GF, Sanchez NP, Flynn TC. Erythema nodosum leprosum ; nature and extent of cutaneous microvascular alterations. J Am Acad Dermatol 1986 ; 14 : 59-69.

5. Katoch VM, Mukherjee A, Girdhar BK. A bacteriological and histopathological study of apparently normal skin in lepromatous leprosy. Lepr India 1878 ; 50 : 38 - 44.

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