Recurrence after apparent clearance is not always drug resistance

Reinfection or insufficient treatment exposure can make ringworm return after seeming to clear.

Re-exposure or incomplete treatmentHousehold contacts, contaminated items or interrupted courses can contribute to relapse.
Underlying predispositionFriction, diabetes or other factors may support recurrent infection.
Resistant Trichophyton infectionEmerging organisms such as T. indotineae may resist some standard therapies.
Steroid-modified dermatophytosisTopical steroids can mask the classic ringworm appearance.
Eczema or psoriasisInflammatory rashes can mimic fungal rings or plaques.

Failure to improve needs diagnosis confirmation

Tinea due to certain dermatophytes may show resistance, but microscopy and culture may be needed to confirm infection first.

Resistant Trichophyton infectionEmerging organisms such as T. indotineae may resist some standard therapies.
Eczema or psoriasisInflammatory rashes can mimic fungal rings or plaques.
Steroid-modified dermatophytosisTopical steroids can mask the classic ringworm appearance.
Intertrigo or yeast-associated diseaseMoist fold rashes may involve different organisms.
Re-exposure or incomplete treatmentHousehold contacts, contaminated items or interrupted courses can contribute to relapse.

Steroids can change the rash, obscure a fungal border and complicate treatment response.

Steroid-modified dermatophytosisTopical steroids can mask the classic ringworm appearance.
Resistant Trichophyton infectionEmerging organisms such as T. indotineae may resist some standard therapies.
Re-exposure or incomplete treatmentHousehold contacts, contaminated items or interrupted courses can contribute to relapse.
Eczema or psoriasisInflammatory rashes can mimic fungal rings or plaques.
Underlying predispositionFriction, diabetes or other factors may support recurrent infection.

Psoriasis, eczema and other inflammatory eruptions can resemble ringworm and will not respond to antifungals.

Eczema or psoriasisInflammatory rashes can mimic fungal rings or plaques.
Intertrigo or yeast-associated diseaseMoist fold rashes may involve different organisms.
Resistant Trichophyton infectionEmerging organisms such as T. indotineae may resist some standard therapies.
Steroid-modified dermatophytosisTopical steroids can mask the classic ringworm appearance.
Re-exposure or incomplete treatmentHousehold contacts, contaminated items or interrupted courses can contribute to relapse.