[Prevalence of dermatomycoses in professional football players : A study based on data of German Bundesliga fitness check-ups (2013-2015) compared to data of the general population]

Onychomycosis in Foot and Toe Malformations

Introduction: It has long been accepted that trauma is one of the most important and frequent predisposing factors for onychomycoses. However, the role of direct trauma in the pathogenesis of fungal nail infections has only recently been elucidated in a series of 32 cases of post-traumatic single-digit onychomycosis. The importance of repeated trauma due to foot and toe abnormalities was rarely investigated. Aimof the study: This is a multicenter single-author observational study over a period of 6 years performed at specialized nail clinics in three countries. All patient photographs taken by the author during this period were screened for toenail alterations, and all toe onychomycosis cases were checked for whether they contained enough information to evaluate potential foot and toe abnormalities. Particular attention was paid to the presence of hallux valgus, hallux valgus interphalangeus, hallux erectus, inward rotation of the big toe, and outward rotation of the little toe, as well as splay foot. Only cases with unequivocal proof of fungal nail infection by either histopathology, mycologic culture, or polymerase chain reaction (PCR) were accepted. Results: Of 1653 cases, 185 were onychomycoses, proven by mycologic culture, PCR, or histopathology. Of these, 179 involved at least one big toenail, and 6 affected one or more lesser toenails. Three patients consulted us for another toenail disease, and onychomycosis was diagnosed as a second disease. Eight patients had a pronounced tinea pedum. Relatively few patients had a normal big toe position (n = 9). Most of the cases had a mild to marked hallux valgus (HV) (105) and a hallux valgus interphalangeus (HVI) (143), while hallux erectus was observed in 43 patients, and the combination of HV and HVI was observed 83 times. Discussion: The very high percentage of foot and toe deformations was surprising. It may be hypothesized that this is not only a pathogenetically important factor but may also play an important role in the localization of the fungal infection, as no marked hallux deviation was noted in onychomycoses that affected the lesser toes only. As the management of onychomycoses is a complex procedure involving the exact diagnosis with a determination of the pathogenic fungus, the nail growth rate, the type of onychomycosis, its duration, and predisposing factors, anomalies of the toe position may be important. Among the most commonly mentioned predisposing factors are peripheral circulatory insufficiency, venous stasis, peripheral neuropathy, immune deficiency, and iatrogenic immunosuppression, whereas foot problems are not given enough attention. Unfortunately, many of these predisposing and aggravating factors are difficult to treat or correct. Generally, when explaining the treatment of onychomycoses to patients, the importance of these orthopedic alterations is not or only insufficiently discussed. In view of the problems encountered with the treatment of toenail mycoses, this attitude should be changed in order to make the patient understand why there is such a low cure rate despite excellent minimal inhibitory drug concentrations in the laboratory.

DNA-Chip-basierte Diagnose der Onychomykose und Tinea pedis

HINTERGRUND UND ZIELE

Onychomykose (OM) und Tinea pedis (TP) sind häufige Pilzinfektionen der Haut. Aktuell basiert die Diagnose vornehmlich auf mikroskopischem Direktnachweis und/oder Kultur. Beide Methoden haben jedoch eine geringe bis mäßige Sensitivität und benötigen teilweise mehrere Wochen, bis endgültige Laborergebnisse vorliegen. Um die Diagnose kutaner Pilzinfektionen zu verbessern, wurden PCR-basierte Methoden entwickelt. Hier haben wir hier die Sensitivität und Spezifität einer Chip-basierten Multiplex-PCR mit mikroskopischen Direktnachweis und verglichen.

PATIENTEN UND METHODIK

In einer monozentrischen, prospektiven Studie wurden bei Patienten mit Verdacht auf OM (n  =  67) oder TP (n  =  73) Schuppenpräparate entnommen und mittels mikroskopischem Direktnachweis, Kultur und DNA-Chip-Technologie der Erregernachweis durchgeführt. In einem weiteren Ansatz wurde überprüft, ob Abstriche als Alternative zur Entnahme eines Schuppenpräparates verwendet werden können. Hierfür wurden 24 weitere OM/TP-Patienten rekrutiert und die Ergebnisse der DNA-Chip-Technologie aus Abstrichen mit denen aus den Schuppenpräparaten verglichen.

ERGEBNISSE

Im Vergleich aller Methoden hatte die DNA-Chip-Technologie die höchste Sensitivität, eine Kombination von DNA-Chip-Technologie mit mikroskopischem Direktnachweis erhöhte dies weiter. Ergebnisse dieser kombinierten Labordiagnostik sind innerhalb von 24 Stunden verfügbar. Der Vergleich der Probenentnahmetechniken (Abstrich beziehungsweise Schuppenpräparat) zeigte vergleichbare Ergebnisse.

SCHLUSSFOLGERUNGEN

Die molekulare Diagnostik (mittels DNA-Chip-Technologie) hat eine hohe Sensitivität für die OM- und TP-Diagnostik, insbesondere in Kombination mit dem mikroskopischen Direktnachweis.