Transmission of Onychomycosis and Dermatophytosis between Household Members: A Scoping Review

Abstract

Onychomycosis is a common fungal infection of the nail, caused by dermatophytes, non-dermatophytes, and yeasts. Predisposing factors include older age, trauma, diabetes, immunosuppression, and previous history of nail psoriasis or tinea pedis. Though many biological risk factors have been well characterized, the role of the environment has been less clear. Studies have found evidence of transmission in 44% to 47% of households with at least one affected individual, but the underlying mechanisms and risk factors for transmission of onychomycosis between household members are incompletely understood. A scoping literature review was performed to characterize and summarize environmental risk factors involved in the transmission of onychomycosis within households. A total of 90 papers met the inclusion criteria, and extracted data was analyzed in an iterative manner. Shared household surfaces may harbor dermatophytes and provide sources for infection. Shared household equipment, including footwear, bedding, and nail tools, may transmit dermatophytes. The persistence of dermatophytes on household cleaning supplies, linen, and pets may serve as lasting sources of infection. Based on these findings, we provide recommendations that aim to interrupt household transmission of onychomycosis. Further investigation of the specific mechanisms behind household spread is needed to break the cycle of transmission, reducing the physical and social impacts of onychomycosis.

Onychomycosis: Recommendations for Diagnosis, Assessment of Treatment Efficacy, and Specialist Referral. The CONSONANCE Consensus Project

“…Although the underlying mechanisms for onychomycosis transmission have not been elucidated, household contact has been identified as a major risk of onychomycosis transmission. Evidence of transmission in almost half of households with at least one affected subject has been reported, highlighting the role of households in the spread of onychomycosis [11].…”

Clinical Manifestations of Human Exposure to Fungi

“…Transmission occurs by direct contact with an infected person or animal (cat, dog, guinea pig, or rabbit) or by contact with the soil. Transmission can also occur indirectly by transfer through wet surfaces (e.g., walkways, changing rooms, and foot washing stations in swimming pool facilities) or by sharing equipment (e.g., combs, hairbrushes, headrests, shaving brushes, and barber chairs, soaps, towels, bedding, and general articles of clothing and footwear, wrestling mats) [ 156 ].…”

Updated Perspectives on the Diagnosis and Management of Onychomycosis

“… 28 , 29 In children, infection with T. tonsurans may occur. 13 Infections with two or more organisms can occur, and mixed dermatophyte-NDM infections account for estimated 3–11% of onychomycosis cases, which may potentially be more difficult to treat and more prone to recurrences. 1 , 4 Importantly, prevalence and infecting pathogen can vary according to the population studied 1 due to differences in geographic location, climates, and daily activities, including professions and personal habits.…”

“…Cases secondary to dermatophyte infections are specifically referred to as tinea unguium. 1,4,13 Infection with NDMs account for about 10% of cases worldwide, with the most common organisms being, Aspergillus spp., Fusarium spp., Acremonium spp., Scopulariopsis brevicaulis, Alternaria alternata, and Neoscytalidium spp. [21][22][23][24] Yeast infections account for up to 10-20% of cases, with the most common pathogen being Candida spp., including C. albicans, C. krusei, C. parapsilosis, C. glabrata and C. tropicalis.…”

“…9,10 Genetics may predispose to developing infection 11,12 and transmission risk increases when members of the same household are infected. 13 Onychomycosis may occur at any age, however prevalence increases with age, 14,15 affecting roughly 50% of patients greater than 70 years old, 16 and is rather rare in the pediatric population, with increased risk seen in children with Down's syndrome or immunodeficiency. 17 Onychomycosis, especially with secondary bacterial infections, can result in local pain and paresthesia, which pose significant psychosocial consequences.…”