infection tends to be limited to the superficial skin. The infection tends to self-resolve so long as the fungal growth does not exceed inflammatory response and desquamation rate is sufficient. If immune response is insufficient, however, infection may progress to chronic inflammation. Immune response Fortunately, dermatophytoses soon progress from the inflammatory stage to spontaneous healing, which is largely cell-mediated. Fungi are destroyed via oxidative pathways by phagocytes both intracellularly and extracellularly. T-cell-mediated response using TH1 cells are likely responsible for controlling infection. It is unclear whether the antifungal antibodies formed in response to the infection play a role in immunity. Infection may become chronic and widespread if the host has a compromised immune system and is receiving treatment that reduces T-lymphocyte function. Also, the responsible species for chronic infections in both normal and immunocompromised patients tends to be Trichophyton rubrum; immune response tends to be hyporeactive. However, "the clinical manifestations of these infections are largely due to delayed-type hypersensitivity responses to these agents rather than from direct effects of the fungus on the host." Diagnosis and identification Usually, dermatophyte infections can be diagnosed by their appearance. However, a confirmatory rapid in-office test can also be conducted, which entails using a scalpel to scrape off a lesion sample from the nail, skin, or scalp and transferring it to a slide. Potassium hydroxide (KOH) is added to the slide and the sample is examined with a microscope to determine presence of hyphae. Care should be taken in procurement of a sample, as false-negative results may occur if the patient is already using an antifungal, if too small a sample is obtained, or if sample from a wrong site is collected. Additionally, a Wood's lamp examination (ultraviolet light) may be used to diagnose specific dermatophytes that fluoresce. Should there be an outbreak or if a patient is not responding well to therapy, sometimes a fungal culture is indicated. A fungal culture is also used when long-term oral therapy is being considered. Fungal culture medium can be used for positive identification of the species. The fungi tend to grow well at 25 degrees Celsius on Sabouraud agar within a few days to a few weeks. In the culture, characteristic septate hyphae can be seen interspersed among the epithelial cells, and the conidia may form either on the hyphae or on conidiophores. Trichophyton tonsurans, the causative agent of tinea capitis (scalp infection) can be seen