Cutaneous Diphtheria Mimicking Pyoderma Gangrenosum

Abstract

made with microscopic evaluation of nail clippings demonstrating PAS-positive branching hyphae forming a dense mass and invading the nail plate. 3 In contrast to the multiple techniques used to diagnose onychomycosis, there are currently no standardized or effective means for the diagnosis of dermatophytoma, even though proper diagnosis has important clinical consequences. Dermatophytoma has been found to be a negative prognostic factor for mycological cure when treating onychomycosis. 4 Optical coherence tomography for nail imaging is a new and growing practice. Healthy nails have been described as having bandlike structures, with varying degrees of intensity and thickness, parallel to the nail surface and a clear demarcation between the nail plate and bed. 5 Abuzahra et al 6 describe OCT findings of onychomycosis as a loss of differentiation of the distinct parallel bands seen in healthy nails and the presence of multiple, irregular, high-scattering, elongated structures parallel to the surface, corresponding to accumulations of fungal hyphae, surrounded by inhomogeneous low-scattering regions. 6 In the present study, OCT findings of nails with dermatophytoma were distinct from those of both healthy nails and nails with onychomycosis. We believe the presence of a sharply demarcated avascular mass lying within an inhomogeneous nail plate without distinct parallel bands and just above the nail bed represents onychomycosis complicated by dermatophytoma. These findings are quickly and easily visualized using structural and dynamic OCT.

Increase in detection of Corynebacterium diphtheriae in Canada: 2006–2019

“…Although the overall numbers were small, a 35% increase of referrals involving C. ulcerans was found, that included strains from humans and animals. Similar increases of both C. diphtheriae and C. ulcerans have been reported in other countries including the United States (7)(8)(9)(10)(11). This increase is likely due in part to the increasingly widespread use of MALDI-TOF systems and precise molecular identification methods.…”

“…In a recent article, we described antimicrobial susceptibility testing (AST) results based on an ancillary study of 195 strains of C. diphtheriae and 20 strains of C. ulcerans (22). Although these species are usually susceptible to first line antibiotics (22), the occasional strain of C. diphtheriae has been found to be penicillin or multidrug resistant (13,23); in some instances, azithromycin may be indicated (10). Of note, the Canadian notifiable disease definition for diphtheria includes C. diphtheriae as well as both C. ulcerans and C. pseudotuberculosis and, if identified in a symptomatic patient, would be classified as a confirmed case (5).…”

“…Cutaneous diphtheria often presents as well-demarcated, sometimes foul-smelling ulcers or as nodules that are slow healing and highly contagious. People who are particularly at risk include those with co-morbidities such as HIV, hepatitis B or C, diabetes, a history of recurrent ulcers, alcohol abuse, a history of intravenous drug use, living in poorer-socioeconomic conditions, homeless shelters or refugee camps, or who travelled to countries where these pathogens are endemic (6)(7)(8)(9)(10)(11). Treatment for cutaneous diphtheria often includes the use of the same systemic antibiotics as those used for respiratory disease, plus the implementation of isolation precautions (6-10) to prevent bacteria from lesions serving as a reservoir for further spread of infection (11,12).…”

Skin infection by Corynebacterium diphtheriae and Streptococcus pyogenes: an unusual association

“…haemolyticum were also isolated in a 50-year-old patient with a recent travel history to Guinea Bissau and mimicking pyoderma gangrenosum [9].…”

Hausse de la détection de Corynebacterium diphtheriae au Canada : de 2006 à 2019

“…La diphtérie cutanée se présente souvent sous forme d'ulcères fétides bien délimités ou de nodules à guérison lente et hautement contagieuses. Les personnes particulièrement à risque sont celles présentant des comorbidités comme le VIH, l'hépatite B ou C, le diabète, des antécédents d'ulcères récurrents, l'abus d'alcool, des antécédents de consommation de drogues injectables, les personnes qui vivent dans de mauvaises conditions socio-économiques, des refuges pour sans-abri ou des camps de réfugiés, ou qui voyagent dans des pays où ces pathogènes sont endémiques (6)(7)(8)(9)(10)(11). Le traitement de la diphtérie cutanée comprend souvent l'utilisation des mêmes antibiotiques à action systémique utilisés pour le traitement des maladies respiratoires, plus la prise de précautions d'isolement (6-10) pour empêcher que les bactéries des lésions servent de réservoir et que l'infection se propage davantage (11,12).…”