Superficial fungal infections in adults in Northern Finland between 2010 and 2021: A register-based study

Background and Aims

Superficial fungal infections are common dermatological reasons to visit a doctor in primary care in Finland. However, their variable clinical picture and minor symptoms may lead to delayed diagnosis. We aimed to investigate the epidemiology and patient profile of fungal infections treated in secondary care over a decade.

Methods

This is a retrospective study including adult patients with a fungal infection in the scalp, nails, or superficial skin diagnosed at the Oulu University Hospital, Finland between the years 2010 and 2021.

Results

There were 573 patients with male predominance (57.6%). All studied fungal infections were more common in the oldest age group (>61 years). The number of fungal infections increased from the year 2017 onward. Only one-third (37.7%) of the patients were referred to the dermatology clinic because of a suspected dermatophyte infection, and in 46.0% of cases, the diagnostic delay exceeded 6 months. The most common fungal infection was tinea pedis (n = 295, 51.5%) followed by tinea unguium (n = 275, 48.0%); as concomitant infection, they were present in 108 (18.8%) of all patients. The most common pathogen causing a fungal infection was Trichophyton rubrum.

Conclusion

During the study period, the incidence of diagnosed superficial fungal skin infections increased. There was a remarkable diagnostic delay from the onset of symptoms to diagnosis in these most common dermatological conditions.