Diagnostic criteria for an IFI are:

1. Presence of a traumatic wound(s).
2. Recurrent necrosis following at least two consecutive surgical debridements.
3. Laboratory evidence of fungal infection following at least two surgical debridements (i.e. mold culture positivity and/or histopathology indicating tissue invasion).9,15 This is usually not available at deployed Role 2 or Role 3 Military Treatment Facilities (MTFs), so clinical suspicion is key to early intervention.
4. Fungal wound infection is often manifested by ‘tinctorial’ or color changes in a wound; early detection of such changes requires repeated inspection by an experienced clinician.18
5. IFIs are often diagnosed through routine histopathological examination of tissue specimens. The evaluation of the performance of periodic acid-Schiff (PAS) and Gomori methenamine silver (GMS) in combat trauma-associated IFI demonstrated that the two stains were 84% concordant with false negative rates of 44% for PAS and 15% for GMS; however, neither stain was significantly superior at identifying fungal elements. Overall, there is no added benefit for increasing diagnostic yield with use of both stains.19
6. Where available, pan-fungal PCR, for identification of filamentous fungi evaluation offers promise for rapid identification of IFI which can lead to a more timely and accurate diagnosis. Compared to histopathology, panfungal PCR was specific (99%), but not as sensitive (63%); however, sensitivity improved to 83% in specimens from sites with angioinvasion.19