Dermatophyte infection extending beyond the superficial stratum corneum is an emerging challenge, particularly in immunocompromised patients. Tinea lucidum, first described in 2014, reflects this shift in pathogenesis, with dermatophytes localizing in the deeper cornified stratum lucidum and, in some cases, occurring without stratum corneum involvement. This creates diagnostic uncertainty when superficial scrapings are used for mycology testing. We retrospectively analyzed skin punch biopsies submitted to a single U.S. laboratory by dermatologists and podiatrists between January 2024 and March 2026. Specimens were obtained from the plantar and dorsal foot, representing moccasin-type tinea pedis with secondary spread to the dorsal surface. Atypical localization in the stratum lucidum occurred in 43.6% (99/227) of cases, including 13.7% (31/227) without detectable fungal elements in the stratum corneum. The dorsal foot more frequently exhibited tinea lucidum than the plantar foot (76.9% [60/78] vs. 26.2% [39/149]; p < 0.0001), potentially reflecting differences in epidermal thickness or underlying immunodeficiency. Higher densities of fungal elements and inflammatory infiltrates revealed by Periodic acid-Schiff and hematoxylin-eosin staining further suggest deeper epidermal invasion; however, the number of samples were limited, and the immune cell populations were not molecularly characterized in this study. For specimens demonstrating dermatophytes localized solely within the stratum lucidum, a survey collected de-identified patient details (responsive rate: 32.3% [10/31]), and sequencing was performed for dermatophyte identification. Trichophyton rubrum was identified in the majority of samples tested (64.5% [20/31]), and histories of immunosuppressive medication use and/or immunosuppressive conditions were noted in several patients. Further studies are needed to validate the histologic criteria and elucidate the immunopathogenesis of this phenomenon.

Our primary aim was to evaluate the relationship between dermatophytosis and disease-modifying antirheumatic drug (DMARD) therapy in patients with rheumatoid arthritis (RA). This prospective study was conducted in a rheumatology clinic between September 2024 and March 2025. All participants were examined for cutaneous fungal infections by a dermatologist. The study included 80 patients and 40 immunocompetent healthy controls. The most common clinical form of dermatophytosis was tinea unguium, followed by tinea pedis, in both the RA and control groups. There were no significant differences between the groups with respect to age, body mass index (BMI), or sex. Smoking was more frequent among RA patients compared with controls. Dermatophytosis was found in 56% of RA patients and 40% of controls. There was no statistically significant difference in the prevalence of dermatophytosis between RA patients and controls. Dermatophytosis was found in 55.4% of the csDMARD group and 58.3% of the b/tsDMARDs group. There was no statistically significant difference in the frequency of dermatophytosis between RA patients receiving csDMARDs and b/tsDMARDs. RA patients were also divided into two groups based on the presence of dermatophytosis. There was a statistically significant difference in the frequency of dermatophytosis according to sex between the groups. There was no statistically significant difference in the frequency of dermatophytosis with respect to DAS28, smoking status, age, BMI, cumulative methotrexate and corticosteroid exposure, and medical therapy between the groups. In our study, the most common clinical form of dermatophytosis was tinea unguium in both the RA and control groups. Although the prevalence of dermatophytosis was slightly higher in the RA population than in controls, there was no significant difference in the prevalence of dermatophytosis between the groups. Although an increased risk could not be demonstrated in the present study, further large-scale prospective studies are needed to clarify the potential relationship.

Chronic eczematous skin disorders that first appear in later life are poorly characterized, partly because existing terminology is inconsistent and often conflates morphologic descriptors with specific diagnoses. This review introduces chronic eczematous eruptions of aging (CEEsA) as an umbrella term, summarizes current knowledge on its epidemiology, etiologies, and clinical presentation, outlines best practices in management, and highlights gaps requiring further investigation. CEEsA frequently present as ill defined, intensely pruritic eruptions on the trunk and extensor limbs, are often refractory to standard topical therapies, and may be precipitated by calcium channel blockers or thiazide diuretics. A structured diagnostic algorithm-incorporating exclusion of mimickers (e.g., tinea pedis-linked auto-eczematization, scabies, contact dermatitis, cutaneous T-cell lymphoma), lesional biopsy, patch testing, and strategic drug withdrawal-is essential before escalating to systemic therapy. This approach helps avoid unnecessary treatment or other etiologies with different management. Although traditional broad spectrum immunosuppressants carry age related safety concerns, emerging targeted agents that dampen type 2 cytokine signaling (dupilumab, tralokinumab) or Janus kinase pathways (upadacitinib) show promising efficacy and tolerability in small case series of CEEsA, including idiopathic forms. Recognizing CEEsA as a distinct clinical construct should streamline nomenclature, sensitize clinicians to reversible drug triggers, and catalyze research into pathophysiology-specific, age appropriate treatments for this under studied geriatric dermatology domain.

Dermatophytosis is commonly caused by anthropophilic or zoophilic fungi. Although factors related to the disease onset have been identified, it is unclear whether these factors influence disease prevalence differently depending on the fungus's ecological niche. Our study aimed to determine the epidemiological characteristics of dermatophytosis caused by anthropophilic versus zoophilic agents. We conducted a retrospective descriptive study (1976-2015) including confirmed cases of dermatophytosis diagnosed by positive mycological cultures in patients treated at the Institute of Tropical Medicine "Daniel Alcides Carrion"-National University of San Marcos, Lima, Peru. Demographic and microbiological data were collected. We used the Chi-square test to evaluate differences in the prevalence of anthropophilic and zoophilic dermatophytosis across the variables of interest. A total of 4961 cases of dermatophytosis were diagnosed. Anthropophilic dermatophytosis was most prevalent in adults, primarily due to Trichophyton rubrum (92.19%) and T. interdigitale (94.16%) (P < 0.001). In contrast, zoophilic dermatophytosis was most prevalent in children, primarily due to Microsporum canis (64.24%) (P < 0.001). Furthermore, anthropophilic dermatophytosis was most prevalent in tinea unguium due to T. rubrum (61.49%) and T. interdigitale (62.12%), as well as in tinea pedis due to T. interdigitale (37.88%) (P < 0.001). Conversely, zoophilic dermatophytosis was most prevalent in tinea capitis due to M. canis (54.88%), as well as in tinea manum and tinea corporis due to T. mentagrophytes (25.71% and 37.71%, respectively) (P < 0.001). According to its ecology, dermatophytosis was related to the age group affected, the clinical form presentation, and a specific etiology.

Tinea pedis (athlete's foot) is a superficial fungal skin infection caused by dermatophytes, most commonly the anthropophilic dermatophyte Trichophyton rubrum. Clinically, it is characterized mainly by scaling, erythema, and fissure formation, and it may present in three primary forms: interdigital, plantar, and vesiculobullous. The infection is often accompanied by mild pruritus; when fissures develop, burning and pain may also occur. Maceration, fissures, and desquamation of the stratum corneum in the interdigital spaces may serve as entry points for β-haemolytic streptococci, thereby increasing the risk of erysipelas. Another complication is the potential spread of infection to the nails, hands, groin, or other body sites. Tinea pedis is primarily indicated for topical antifungal therapy. Over-the-counter antifungal agents include imidazoles, allylamines, thiocarbamates, and undecylenic acid derivatives. Based on an analysis of clinical studies, their efficacy and duration of treatment have been compared.

Nitric oxide (NO)-based therapeutics represent a promising modality for overcoming the challenges of treating dermatophyte infections within keratinized tissues.