Differential Diagnosis of Skin Ulcers in a Mycobacterium ulcerans Endemic Area: Data from a Prospective Study in Cameroon.

Laurence Toutous Trellu,Barbara Rusch,Yolanda K Mueller,Eric Comte,Paul Atangana,Earnest Njih Tabah,Jean-François Etard,Didier Junior Mboua,Patrick Nkemenang,Geneviève Ehounou

doi:10.1371/journal.pntd.0004385

Abstract

BackgroundClinical diagnosis of Buruli ulcer (BU) due to Mycobacterium ulcerans can be challenging. We aimed to specify the differential diagnosis of skin lesions in a BU endemic area.MethodWe conducted a prospective diagnostic study in Akonolinga, Cameroon. Patients presenting with a skin ulcer suspect of BU were included. M. ulcerans was detected using swabs for Ziehl-Neelsen staining, PCR and culture. Skin punch biopsies were taken and reviewed by two histopathologists. Photographs of the lesions were taken and independently reviewed by two dermatologists. Final diagnosis was based on consensus, combining the results of laboratory tests and expert opinion.Results/ DiscussionBetween October 2011 and December 2013, 327 patients with ulcerative lesions were included. Median age was 37 years (0 to 87), 65% were males, and 19% HIV-positive. BU was considered the final diagnosis for 27% of the lesions, 85% of which had at least one positive laboratory test. Differential diagnoses were vascular lesions (22%), bacterial infections (21%), post-traumatic (8%), fistulated osteomyelitis (6%), neoplasia (5%), inflammatory lesions (3%), hemopathies and other systemic diseases (2%) and others (2%). The proportion of BU was similar between HIV-positive and HIV-negative patients (27.0% vs. 26.5%; p = 0.940). Half of children below 15 years of age were diagnosed with BU, compared to 26.8% and 13.9% among individuals 15 to 44 years of age and above, respectively (chi2 p<0.001). Children had more superficial bacterial infections (24.3%) and osteomyelitis (11.4%).ConclusionWe described differential diagnosis of skin lesions in a BU endemic area, stratifying results by age and HIV-status.

Highlights

Infection by M. ulcerans, more commonly known as Buruli Ulcer (BU), is a neglected tropical disease that has been reported in33 countries in Africa, the Americas, Asia and the Western Pacific [1]
We described differential diagnosis of skin lesions in a Buruli ulcer (BU) endemic area, stratifying results by age and HIV-status
We aimed to describe the differential diagnoses for lesions with suspect M. ulcerans infection in central Cameroon

Summary

Introduction

Infection by M. ulcerans, more commonly known as Buruli Ulcer (BU), is a neglected tropical disease that has been reported in countries in Africa, the Americas, Asia and the Western Pacific [1]. M. ulcerans infection generally begins with a localised, itchy skin lesion which evolves into localized (nodule) or diffuse (oedema) swelling, or as an indurated plaque. The laboratory technique most commonly used in the field for BU diagnosis is direct examination by microscopy using a Ziehl-Neelsen (ZN) stained smear in search of Alcohol- and Acid-Fast bacilli, with a sensitivity of ZN of approximately 40% [4, 5]. The same staining technique can be used for non-ulcerated plaques using fine needle aspiration [6]. Clinical diagnosis of Buruli ulcer (BU) due to Mycobacterium ulcerans can be challenging. We aimed to specify the differential diagnosis of skin lesions in a BU endemic area

Objectives

Methods

Results

Conclusion