What are deep tissue and superficial fungal infections?

A fungal infection can take two forms: a superficial fungal infection or a deep tissue fungal infection. Superficial infection affects only the skin or outside of the body, while a deep tissue infection means it attacks internal parts beneath the skin. Superficial fungal infections include yeast infections, athlete's foot, and ringworm. Deep tissue infections can include those that start in the lungs, as well as those that start as superficial infections and spread via the blood into organs, internal tissues, bone, and sometimes into the brain.