Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 6-14: Fungal Infections of the Skin + Key Features Download Section PDF Listen +++ +++ Essentials of Diagnosis ++ Most often present with asymptomatic scaling May progress to fissuring or maceration in toe web spaces Common cofactor in lower extremity cellulitis Itching, burning, and stinging of interdigital web; scaling palms and soles; vesicles of soles in inflammatory cases KOH preparation or fungal culture of skin scapings is usually positive +++ General Considerations ++ An extremely common acute or chronic dermatosis Most infections are caused by Trichophyton species Interdigital tinea pedis is the most common predisposing cause of lower extremity cellulitis in healthy individuals + Clinical Findings Download Section PDF Listen +++ +++ Symptoms and Signs ++ Itching, burning, and stinging Pain may indicate secondary infection with complicating cellulitis Tinea pedis has several presentations that vary with the location On the sole and heel, may appear as chronic noninflammatory scaling, occasionally with thickening and cracking of the epidermis; this may extend over the sides of the feet in a "moccasin" distribution Often appears as a scaling or fissuring of the toe webs, perhaps with sodden maceration There may be grouped vesicles distributed anywhere on the soles or palms, generalized exfoliation of the skin of the soles, or nail involvement in the form of discoloration and thickening and crumbling of the nail plate +++ Differential Diagnosis ++ Erythrasma Psoriasis Contact dermatitis (from shoes) will often involve the dorsal surfaces and will respond to topical or systemic corticosteroids Dyshidrosis (pomphylox) Scabies Pitted keratolysis Tinea pedis must be differentiated from other skin conditions involving the same areas, such as Interdigital erythrasma (use Wood light) Psoriasis (repeated fungal cultures should be negative) + Diagnosis Download Section PDF Listen +++ +++ Laboratory Tests ++ As the web spaces become more macerated, the KOH preparation and fungal culture are less often positive because bacterial species begin to dominate + Treatment Download Section PDF Listen +++ +++ Medications +++ Local measures ++ See Table 6–2 Macerated stage—treat with aluminum subacetate solution soaks for 20 min twice daily Broad-spectrum antifungal creams and solutions (containing imidazoles or ciclopirox) will help combat diphtheroids and other gram-positive organisms present at this stage and alone may be adequate therapy If topical imidazoles fail, try 1 week of once-daily allylamine treatment (terbinafine or butenafine) Dry and scaly stage—use any of the agents listed in Table 6–2 The addition of urea 10–20% lotion or cream may increase the efficacy of topical treatments in thick ("moccasin") tinea of the soles +++ Systemic measures ++ Itraconazole, 200 mg once daily orally for 2 weeks or 400 mg once daily for 1 week, or terbinafine, 250 mg once daily orally for 2–4 weeks, may be used in refractory cases +++ Therapeutic Procedures ++ Socks should be changed frequently, and absorbent nonsynthetic socks are preferred + Outcome Download Section PDF Listen +++ +++ Prognosis ++ For many individuals, tinea pedis is a chronic affliction, temporarily cleared by therapy only to recur +++ Prevention ++ The essential factor in prevention is personal hygiene Wear open-toed sandals if possible; use rubber or wooden sandals in community showers and bathing places Careful drying between the toes after showering is essential; a hair dryer used on low setting may be helpful Powders containing antifungal agents (eg, Zeasorb-AF) or chronic use of antifungal creams may prevent recurrences Regular examination of the feet of diabetic patients for evidence of scaling and fissuring and treatment of any identified tinea pedis may prevent complications +++ When to Refer ++ If there is a question about the diagnosis, if recommended therapy is ineffective, or if specialized treatment is necessary + References Download Section PDF Listen +++ + +Goiset A et al. Characteristics, associated diseases, and management of gram-negative toe-web infection: a French experience. Acta Derm Venereol. 2019 Nov 1;99(12):1121–6. [PubMed: 31502652] + +Kramer ON et al. Clinical presentation of terbinafine-induced severe liver injury and the value of laboratory monitoring: a critically appraised topic. Br J Dermatol. 2017 Nov;177(5):1279–84. [PubMed: 28762471] + +Rajagopalan M et al. Expert Consensus on The Management of Dermatophytosis in India (ECTODERM India). BMC Dermatol. 2018 Jul 24;18(1):6. [PubMed: 30041646]