Tinea Manuum & Pedis

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

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)

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

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

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