Comparison of potassium hydroxide mount and mycological culture with histopathologic examination using periodic acid-Schiff staining of the nail clippings in the diagnosis of onychomycosis.

BACKGROUND: Onychomycosis is a common problem noticed in clinical practice. Currently available standard laboratory methods show inconsistent sensitivity; hence there is a need for newer methods of detection. AIMS: This study involves comparison of standard laboratory tests in the diagnosis of onychomycosis, namely, potassium hydroxide mount (KOH mount) and mycological culture, with histopathologic examination using periodic acid-Schiff (PAS) staining of the nail clippings. METHODS: A total of 101 patients with clinically suspected onychomycosis were selected. Nail scrapings and clippings were subjected to KOH mount for direct microscopic examination, culture using Sabouraud's dextrose agar (with and without antibiotics) and histopathologic examination with PAS staining (HP/PAS). Statistical analysis was done by McNemar's test. RESULTS: Direct microscopy with KOH mount, mycological culture, and HP/PAS showed positive results in 54 (53%), 35 (35%), and 76 (75%) patients respectively. Laboratory evidence of fungal infection was obtained in 84 samples by at least one of these three methods. Using this as the denominator, HP/PAS had a sensitivity of 90%, which was significantly higher compared to that of KOH mount (64%) or mycological culture (42%). CONCLUSIONS: Histopathologic diagnosis with PAS staining of nail clippings was the most sensitive among the tests. It was easy to perform, rapid, and gave significantly higher rates of detection of onychomycosis compared to the standard methods, namely KOH mount and mycological culture.

Clinico-mycological profile of dermatophytosis in a reference centre for leprosy and dermatological diseases in Addis Ababa.

To assess the clinical and fungal species spectrum of dermatophyte infection in a reference centre in Addis Ababa, 539 dermatological patients with signs of dermatophytosis were investigated. Seventy-one percent were female and 29% male, aged 2-66 years (median 9). Four hundred-fifteen (77%) had at least one skin lesion. Tinea capitis was diagnosed in 138/155 males (89%) as compared to 214/384 females (40%) (p < 0.05). T. capitis was diagnosed in 69% of the 374 children. Fingernails were affected in 132/145 (91%) of onychomycosis, 118 (90%) of these patients were females and 14 males (p < 0.05). Tinea corporis was observed in 45, and other types of tinea in 12 patients. Thirty-six percent of all patients had also other skin lesions, mostly impetigo. Of 490 cultured samples 364 (74%) grew dermatophytes: Trichophyton violaceum in 84%, Trichophyton verrucosum in 9.6%, Trichophyton tonsurans in 1.4% and T. rubrum in 0.5%. Additionally, 15 isolates were identified as white variants of T. violaceum, in 3 cases confirmed by sequencing of the rDNA ITS 2 region. T. capitis in young males and T. unguium of fingernails in females were the most common manifestations of dermatophytosis in Addis Ababa, usually caused by T.violaceum.

Paquioniquia congênita(Sindrome de Jadassohn Lewandowsky) / Pachyonychia Congenita (Syndrome of Jadassohn Lewandowsky)

A sin drome de jadassohn lewandowsky ou paquioniquia conjenita (PC) hereditaria autossomica dominante de ocorrencia rara com expressividade fenotipica altamente variavel. Caracteriza-se pela formação de quantidades excessivas de queratina nas unhas pele e mucosas, manifestada por hiperceratose ungueal simetrica hiperceratose palmoplantar e leucoceratose folicular. Apresenta-se o caso de um jovem portador dessa anomaliacom onicodistrofa generalizada de mâos e pes, hiperceratose palmoplantar dentes natis maculas no dorso comedões e cistos multiplos pelo corpo paquitriquia e placas alopecias ocipitais. Neste artigo citam-se aspectos geneticos compilam-se manifestações clinicas revisam-se propostas de classificação descreve-se o quadro histologico e aventam-se as possibilidades terapeiticas da PC.