การวินิจฉัยโรคทางไขมันในนิ้วเท้านอกจากการพยายามที่มีอาการทางทางคลินิกแล้ว ยังต้องใช้วิธีตรวจสอบเสริมที่สำคัญอีกด้วย วิธีตรวจสอบที่ใช้บ่อยที่สุดคือ
1Collect enough samples is the key, for distal subungal type can be used with a spatula, dental scraper, and nail lifter to take nail subungual debris, and for proximal subungal type can be used with a nail drill or scalpel. For white superficial type, a spatula can be used to scrape off the nail scales near the nail bed at the junction of the diseased area and the normal area, and add , Mycological examination10% KOH direct microscopy. The presence of branching hyphae can support the diagnosis, and phaeomycetes, penicillium, aspergillus, cephalosporin, fusarium, scabies and Candida albicans can form hyphae and pseudohyphae and be confused with dermatophytes.
2, Histopathology The stratum corneum is thickened and loose, the keratinocytes are arranged in a reticular pattern, and there is varying degrees of damage, visible cracks and cavities. If there are thin, regular hyphae or arthrospores in the nail plate, it suggests dermatophytosis. The hyphae often grow horizontally, some obliquely or vertically, some along the cavity wall, usually located in the outer or inner layer of the nail plate. When the nail plate is severely damaged, the entire layer of the nail plate can be seen with dense arrangement of hyphae and spores.