Umbilicated Papules as a Rare Manifestation of Borderline Lepromatous Leprosy

The word "umbilicated" is derived from the Latin word "umbilicatus", meaning depressed in the center, similar to a navel. Dermatology possesses numerous conditions that may manifest with umbilicated lesions, histoid leprosy being one of them. We hereby report an interesting case of borderline lepromatous leprosy who presented with numerous umbilicated papules.

A 67-year-old man presented with multiple asymptomatic skin-colored lesions on his face, upper trunk, and upper extremities, of duration 3 months. Cutaneous examination revealed numerous umbilicated papules on the face, ears, and back (dimensions varying from 0.4 to 3 cms in diameter). Some of the lesions on the back were minute nonumbilicated papules and some of them were larger and umbilicated gradually acquiring an annular configuration [Figures 1 and 2]. To note, the lesions were bilateral but asymmetrical. Bilateral radial, ulnar, and common peroneal nerves were enlarged but nontender. Glove and stocking anesthesia was present in a bilateral asymmetrical manner. Madarosis and ear lobe infiltration were absent. Motor nerve examination, and systemic and ocular examination were within normal limits. Slit skin smear revealed a bacteriologic index of 6+. Histopathology of a lesion from the back showed a diffuse collection of foamy macrophages and histiocytes, filled with globi of acid-fast bacilli [Figure 3]. A diagnosis of borderline lepromatous leprosy moving toward subpolar lepromatous leprosy was made. With questioning, a history of leprosy in a neighbor was elicited. The patient was prescribed standard adult multidrug therapy with rifampicin, dapsone, and clofazimine for 12 months.

Figure 1.

Umbilicated papules on the face

Figure 2.

Umbilicated papules on the back. Other than papules, there are some annular plaques on the back

Figure 3.

Photomicrograph showing a diffuse collection of foamy macrophages and histocytes, teeming with acid-fast bacilli (Mycobaterium leprae), (Fite Faraco stain, 400×)

Lepromatous leprosy is a highly infectious pole of the spectrum of the disease. It usually presents with hypopigmented macules, patches, papules, nodules, and diffuse infiltration. Umbilicated lesions are rarely seen in leprosy and may be seen in histoid, lepromatous, and borderline lepromatous leprosy.[1,2,3,4] We believe that such umbilicated lesions are a part of disease evolution, and may be seen when the minute papules progress toward acquiring annular configuration (as evident from the examination of the lesions on the back).[5] Another possible reason might be epidermal necrosis in rapidly evolving papulonodules (as seen in molluscum contagiosum)[6] due to dermal infiltration. However, the exact pathogenesis behind the development of these lesions is not clear. Borderline lepromatous leprosy typically presents with shiny discrete macules, papulo-nodules, and plaques (with a tendency to symmetry), with slight impairment of sensation over the lesions. Peripheral nerve involvement is notable, but asymmetrical. The relevant clinical differentials for our case are summarized in Table 1.

Table 1.

Clinical differentials of the index case

Clinical differential	Salient features
Histoid leprosy	Skin colored dome-shaped papules and nodules on a background of normal skin
Secondary syphilis	Asymptomatic bilaterally symmetrical coppery red-colored macules, papules, plaques, and nodules; mucous patch; condyloma lata and generalized lymphadenopathy
Sarcoidosis	Pleomorphic presentation (macules, papules, plaques, and nodules of varying sizes and shapes)
Cryptococcosis and histoplasmosis	Papules with central umbilication, often undergoing ulceration, in a background of immunosuppression

Namisato et al. proposed that a dense, rapidly growing, granulomatous, upper dermal infiltrate could lead to extrusion of the intradermal granulomas and acid-fast bacilli. The follicular epithelium may have a vital role to play in this process of "transepidermal elimination", similar to perforating disorders. It is also believed that the presence of acid-fast bacilli adjacent to the central part of the papules could be responsible for the elimination and community spread of lepra bacilli from such highly infectious patients.[7] Umbilicated lesions similar to our case may exhibit the phenomenon of transepidermal elimination, thereby contributing to the spread of the disease.

A high index of suspicion is required for clinching a prompt diagnosis, because unidentified cases of lepromatous leprosy, with a high bacillary load (like our case) can lead to transmission of the disease in an endemic country like India.

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The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.