A 36-year-old male presented with a history of redness and a slowly growing swelling in his right eye since the past six months. Visual acuity was 20/20 both eyes. Slit-lamp biomicroscopy showed mild perilimbal congestion along with an inferotemporal vascularized, solid, rubbery, nontender limbal mass fixed to the underlying tissues. The mass was approximately 5 mm in diameter and was elevated 2 mm above the ocular surface. It was located between the 6 and 8’o clock position. The conjunctiva over the swelling was edematous and freely mobile with engorged conjunctival blood vessels traversing it. There was an area of sectoral interstitial keratitis adjacent to the lesion with deep and superficial vascularization of the cornea [Figure 1a]. Anterior segment was quiet and fundus unremarkable. General physical examination revealed bilateral thickened ulnar and popliteal nerves. Multiple nontender, nonhypoaesthetic, erythematous nodules were seen in the lumber region [Figure 2]. Slit-skin smears were positive for lepra bacilli. Excisional biopsy of the limbal mass showed subepithelial sheets of foamy histiocytes. In addition, numerous globi and fragmented lepra bacillary aggregates were observed, consistent with the diagnosis of histoid leprosy [Figure 1b]. Multibacillary multidrug (MDR-MB) therapy (rifampin, clofazimine, and dapsone) proposed by the World Health Organization (WHO) was initiated. After a year of follow-up, his perilimbal congestion and conjunctival edema resolved completely and nodular lesions on the lumbar region disappeared.
Figure 1.
(a) Slit-lamp biomicroscopy showing mild perilimbal congestion with the presence of an inferotemporal vascularised, solid, rubbery, non-tender limbal mass and an adjacernt area of interstitial keratitis. (b) Histopathology showing sheets of foamy histiocytes, numerous globi and fragmented lepra bacillary aggregates
Figure 2.
Erythematous nodules seen in the lower lumber region
A leproma is a superficial, circumscribed, discrete granulomatous nodule rich in lepra bacilli. Its incidence in eye is reported to be 0.75–1% among lepromatous leprosy patients.[1] Most cases of lepromas in eye are reported to be in relation to the ciliary body with uveitis and rarely in limbus. Ocular involvement in leprosy may be due to primary infection of the ocular adenexa, direct invasion with gradual spread to the conjunctiva and cornea, or secondary to nerve involvement.[1] Histoid type of leprosy is an extremely rare variant of lepromatous leprosy. It is an uncommon form of multibacillary infection.[2] Histoid leprosy cases represent resistant bacilli and a highly active lepromatous disease process.[2] Mostly, the ocular clinical picture of leprosy is mixed with the involvement of several ocular structures.[3] However, in our case, the ocular involvement was confined to the limbus and cornea only, with no other ocular involvement.
The patients need to be treated with WHO recommended MDR-MB therapy. Follow-up is initially weekly for a month, then monthly for a year till the multidrug therapy is given, and then routine 6 monthly follow-up until 5 years. Treatment response is good and relapse rate is low; usually a single full course of therapy is sufficient. The WHO has estimated a risk of relapse of 0.77% for MB and 1.07% for paucibacillary (PB) patients 9 years after stopping MDT. Various other studies using person-years of observation have estimated relapse rates varying from 0.65 to 3.0% for PB and 0.02 to 0.8% for MB leprosy.[4] The majority of relapses occur in the first 3 years of treatment. If an individual does not relapse within the first 5–6 years, his/her risk of relapsing is negligible.[4]
Occurrence of such cases does not bode well for a country like India where leprosy was eradicated as a public health problem in 2005.[5] This case highlights the importance of maintaining a high index of suspicion for diagnosing leprosy in view of its declining incidence, especially in densely populated countries like India where such patients, if not diagnosed and managed timely, can act as potential reservoirs of infection in the community.
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References
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