Tinea capitis (scalp ringworm) is a fungal dermatophyte infection of scalp hair follicles and surrounding skin that afflicts 3-8% of the U.S. pediatric population. The infection is more common in children than adults, and it results in hair loss, inflammation, itching, scaling and pustules. Tinea capitis is also a major health care disparity because it occurs predominantly among individuals from disadvantaged socioeconomic backgrounds and sub-Saharan African descent. In addition to the medical impact on the patient, tinea capitis also stigmatizes disadvantaged children (e.g. increased bullying, social ostracism), keeps them from school until treated, and adds health care cost in a population least able to pay.
Diagnostic challenges. The current gold standards for diagnosis of tinea capitis are microscopy and fungal culture. Microscopy requires a high degree of skill, is expensive and is most often done on samples that have been shipped to reference laboratories, which means results take several days. Fungal culture also requires sending a sample to a reference lab, and results are generally not available for 2-4 weeks. Consequently, many doctors diagnose the infection based on the patient’s clinical presentation alone. But because the symptoms of tinea capitis are difficult to distinguish from other skin disorders, many patients with tinea capitis fail to receive appropriate treatment with anti-fungal drugs, while other patients without tinea capitis receive unnecessarily anti-fungal treatment.
It is critical to get the diagnosis and treatment plan right. Failure to provide anti-fungal treatment to patients with tinea capitis can result in more severe disease for the patient and continued disease transmission in the community. Conversely, incorrectly prescribing anti-fungal drugs to patients without tinea capitis can result in unnecessary risk exposure, because the anti-fungals used to treat tinea capitis are oral drugs that must be taken for at least 6 weeks and have potential for serious systemic side effects.
DxDiscovery solution. Our solution is to produce a point-of-care diagnostic for tinea capitis that is rapid, accurate, affordable, and deliverable to sites that serve health disparity populations. The goal is to correctly diagnose tinea capitis during the patient’s first healthcare visit, so that patients can receive prompt, appropriate treatment and return to their daily lives.
The target population will be individuals with a clinical presentation of tinea capitis. The approach will be an immunoassay for cell wall polysaccharides as biomarkers for dermatophyte fungi. The product will be a rapid (<10 min) and inexpensive lateral flow immunoassay (LFIA) that will directly identify the presence of dermatophyte fungi in skin scrapings and hair. A positive result would trigger immediate treatment.
We have already developed a multi-step, research-grade LFIA that is reactive with galactomannans of all major dermatophytes as well as with extracts of clinical samples from several patients with dermatophyte infection. The objective of this study is to move the current research-grade LFIA to a format suitable for point-of-care (POC) use, which will involve i) developing sample treatment and biomarker extraction procedures that can be performed in less than 10min in a primary care physician office, ii) optimizing a one-step LFIA for easy use at the POC, and iii) evaluating the LFIA with clinical samples.
Market opportunity. Approximately 450,000 patients in the United States are diagnosed with tinea capitis every year. In addition, the same pathogen that causes tinea capitis, also causes onychomycosis (fungal infection of the toenails and fingernails). Onychomycosis is also a health care disparity issue, in that the risk of disease is higher in diabetic patients, elderly patients, and patients from Native American descent. Onychomycosis is diagnosed in over 1.2M patients in the United States every year.
R&D funding. A small business innovation research (SBIR) Phase I grant from the National Institute of Biomedical Imaging and Bioengineering has been awarded. The project has a $390,000 R&D budget over two years.