Laryngeal involvement causing dysphonia in a 29 year old nursing mother with lepromatous leprosy

Leprosy is a granulomatous disease that mainly affects the skin and peripheral nerves. It is caused by infection with mycobacterium leprae or mycobacterium lepromatosus. In most instances, diagnosis of leprosy can easily be made based on the clinical signs and symptoms. However, when patients present with atypical features, clinical diagnosis can be a challenge. We report a case of a nursing mother with lepromatous leprosy who presented with dysphonia and skin lesions initially thought to be a deep cutaneous mycosis.


Introduction
Leprosy is a granulomatous disease caused by mycobacterium leprae and less frequently by mycobacterium lepromatosus [1]. A delay in treatment of leprosy is usually a consequence of delayed diagnosis rather than due to absence of recommended drugs. When typical cutaneous lesions and peripheral nerve involvement are the presenting features, diagnosis of leprosy is easy and early.
However, diagnosis can be elusive when less common presentations such as laryngeal and ocular manifestations are encountered.
Zambia is considered a low prevalence area for leprosy.
Nevertheless, like some countries in Africa we continue to have several cases of the disease diagnosed every year. We report the case of a woman referred to us from an area with a leprosy center who had a pattern of disease not initially attributed to leprosy.

Patient and observation
A 29 year old woman was referred to the university teaching hospital (UTH) from a central hospital for further evaluation and management of generalized skin lesions which had been present for several years. The skin lesions were initially thought to be psoriasis or syphilis. They had started off as painful growths under the skin which would eventually discharge mucoid fluid. Over the past 2 to 3 months prior to presentation at UTH, she experienced an increase in the number and size of skin lesions with involvement of previously unaffected areas like the face. She also developed a persistent sore throat with associated dysphonia and occasional fevers.  Table 1). A final diagnosis of multibacillary leprosy was made. Treatment with dapsone, rifampicin, and clofazimine was commenced with a plan to follow up her infant for the next five years. She returned for a review about a month after commencing treatment and her lesions had reduced in size and number (Figure   1 (B)), with normalization of her voice.

Discussion
This case highlights some atypical and misleading presentations of leprosy. Classical features of leprosy are dependent on the clinical subtype and may include peripheral nerve enlargement and characteristic anaesthetic cutaneous lesions [2]. However, a handful of patients may have an atypical presentation which may not readily be recognized as leprosy. This patient had skin lesions that may be encountered in deep cutaneous mycoses like disseminated cutaneous sporotrichosis [3]. Other atypical presentations reported in the literature include ocular (keratitis, uveitis) [4] and upper airway involvement (laryngitis) [2]. Leprosy has been classified into 2 polar forms (lepromatous and tuberculoid) with 3 borderline disease patterns in between [5]. This is a result of a genetically predetermined immune response in different individuals [6]. The The BCG vaccine which was initially developed to provide protection against tuberculosis also protects against leprosy. Furthermore, chemoprophylaxis with rifampicin has been shown to be effective [8] and is widely used in countries still battling high incidence rates of leprosy. Exposed infants are usually asymptomatic, but this is the period of acquisition for childhood and adolescent leprosy, hence the need to follow up the infant and his siblings. However, whether they become symptomatic and the clinical subtype will be determined by heritable factors.

Conclusion
Most cases of lepromatous leprosy are clinically obvious. However, when it presents in an unusual manner, histopathology is a very valuable tool in distinguishing it from other disease entities. It is vital to diagnose and commence treatment early in patients presenting with laryngeal involvement so as to prevent fatal complications such as upper airway obstruction in leprosy patients.

Competing interests
The authors declare no competing interests.

Authors' contributions
The authors have read and approuved the final version of this manuscript.