Concurrent skin and nerve histology in leprosy and its role in the classification of leprosy

Challenging diagnosis of leprosy in a psychotic homeless patient with atypical clinical manifestations: an interesting case report

Background

A decision to diagnose certain skin diseases in patient undergoing psychotic break is challenging; this includes establishing the diagnosis of leprosy. Diagnosis of leprosy is established if there is at least one of the three cardinal signs of leprosy. Histopathological examination is not a gold standard, but remains useful in atypical or clinically suspicious cases.

Case presentation

We report for the first time, an interesting case of leprosy with atypical clinical manifestations in a psychotic homeless male with unknown history of present illness. Upon examination, hypopigmented macules, hyperpigmented macules, and plaques were observed, with unclear sensation impairment. Peripheral nerve thickening and acid-fast bacilli from slit-skin smear were not found. Histopathological examination from hypopigmented macule on the upper right limb showed no granulomatous reaction and other histopathological features of leprosy. Although the condition did not fulfill the cardinal signs of leprosy, we found lagophthalmos, claw hands, pseudomutilation of fingers and toes. Therefore, the diagnosis of suspected leprosy was established. The patient was hospitalized and attempts to administer oral rifampicin and clofazimine were made. Several days after treatment, annular erythematous macules appeared on the patient’s face, abdomen, and back. Histopathological examination results on sample taken from erythematous macule and right sural nerve were consistent with the diagnosis of leprosy with reversal reaction.

Conclusion

In certain conditions, histopathological examination of the skin and nerves are a highly rewarding test in establishing a diagnosis of leprosy.