Several dimorphic fungi have saprophytic counterparts with similar, look-alike microscopic features. These are shown in the table below:
| Dimorphic Fungus | Saprophytic Mold Counterpart | Common Microscopic Morphologic Features |
| Blastomyces dermatitidis | Chrysosporium species Scedosporium species also produces single, oval microconidia similar in appearance to those of B. dermatitidis. However, the conidia of Scedosporium species are slightly larger and have a dark pigmentation. | Production of small, smooth, oval microconidia, each supported by a delicate conidiophore ("lollipop"). |
| Histoplasma capsulatium | Sepedonium species | Production of large, spherical macroconidia, which, when mature may have prickly surfaces. |
| Coccidioides immitis | Malbranchia species | Production of alternate staining arthroconidia. |
These methods can be used to differentiate the dimorphic fungi from their saprophytic counterparts:
- The dimorphic fungus can be converted to a yeast form by incubation at body temperature and the saprophytic mold cannot.
- Dimorphic fungi will grow in culture media containing cycloheximide and the saprophytic molds will not.
- Dimorphic fungi will show positive reactions in antigen-specific nucleic acid probe assays.
