Juvenile Plantar Dermatosis (atopic winter feet, forefoot dermatosis, sweaty sock dermatitis, peridigital dermatosis, dermatitis plantaris sicca, moon-boot foot syndrome)

Are You Confident of the Diagnosis?

What you should be alert for in the history

Clinical history is often significant for occlusive footwear (e.g. rubber boots, winter boots), extended periods of exposure to moist socks or shoes, and possibly hyperhidrosis of the feet. Always ask about the patient’s most recent footwear. This condition has a predilection for children and young adolescents. It is also important to consider a personal or family history of atopic dermatitis or atopy.

Characteristic findings on physical examination

Clinical exam demonstrates shiny glazed erythematous patches containing fissures and desquamation on weight-bearing regions of the foot, specifically the plantar forefoot, great toe, and occasionally the heel (Figure 1). The interdigital spaces and nails are spared. Fissures in the these areas may be painful. A complete skin exam may provide other indicators of atopic dermatitis.

Figure 1.

Juvenile plantar dermatosis. Shiny, glazed erythematous patches with fissures and desquamation on the forefoot and heels. (Courtesy of Richard Haber, MD, FRCPC, Division of Dermatology, University of Calgary, Calgary, Alberta, Canada)

Expected results of diagnostic studies

Laboratory studies are unnecessary, as juvenile plantar dermatosis is clinically unique. Furthermore, a skin biopsy is rarely performed and may cause unnecessary morbidity in a young child for a condition that has a relatively benign course and spontaneous resolution.

Histopathic features of juvenile plantar dermatosis include uniform parakeratosis, psorasiform acanthosis with focal loss of the granular cell layer, spongiosis, spongiotic vesiculation, paranuclear vacuolization of epidermal keratinocytes, and inflammatory cellular infiltrate around the acrosyringium. Furthermore, inflammatory changes around the sweat ducts near the entry point into the epidermis can also been seen.

Diagnosis confirmation

The differential diagnosis includes the following:

– Keratolysis exfoliativa—similar appearance to juvenile plantar dermatosis, but usually affects the hands

– Contact dermatitis (irritant, allergic)—inquire about a history of new footwear and dermatitis affecting the dorsal aspect of the feet. Patch testing may be considered for identifying specific contact allergens.

– Dyshidrotic eczema—look for tiny deep-seated vesicles on the palms, lateral fingers, and soles

– Plantar psoriasis—examine the patient for other psoriatic lesions on the scalp, trunk, and extremities, and look for nail dystrophy (i.e. pitting, onycholysis, etc.). Inquire about a family history of psoriasis, nail dystrophy, and psoriatic arthritis.

– Tinea pedis—look for fine scaling and/or maceration of the instep and interdigital spaces as well as onychomycosis. Potassium hydroxide test to visualize microscopic fungal elements or fungal cultures may be performed. Notably, tinea pedis is uncommon in children.

Who is at Risk for Developing this Disease?

Juvenile plantar dermatosis usually affects patients between ages 3 and 15 years old (peak onset is between 4 and 8 years old). These patients may also have an atopic diathesis (e.g. atopic dermatitis, asthma, and allergic rhinitis).

What is the Cause of the Disease?

The etiology of juvenile plantar dermatosis is likely multifactorial.

Various theories have been proposed, but many are controversial. Theories of the etiology include:

  • Poor breathability of fabrics used in socks and shoes (e.g. synthetic fabrics, occlusive insulated winter boots, rubber boots, etc.)

  • Repetitive frictional forces from physical activity

  • Hyperhidrosis, particularly in the summer (although some authors disagree with seasonal variability). A genetic predisposition to atopy is likely contributory.

Systemic Implications and Complications

While juvenile plantar dermatosis likely results in compromised skin barrier function, the reported risk of secondary infection with this condition is low.

Treatment Options

Treatment options are summarized in Table I.

Table I.
General Measures Medical Interventions
Wear breathable socks (i.e. cotton only, avoid synthetic materials) Thick emollients or ointments (e.g. petroleum jelly at night under a sock). It is important to warn patients about the potential fall risk on smooth or polished surfaces.
Frequent changing of socks to keep the feet dry Barrier creams (containing dimethicone) during the day to prevent maceration
Well-fitting and breathable footwear (e.g. sandals, leather) Topical corticosteroids for short periods (i.e. 1-2 weeks), particularly if inflammation (e.g. erythema) or pruritus is present. Examples include mometasone furoate 0.1%, betamethasone valerate 0.05 to 0.1% ointments
Avoid plastic or rubber shoes (especially on the soles) Topical tacrolimus 0.1% ointment
  Liquid skin glues to seal fissures

Optimal Therapeutic Approach for this Disease

The most important goal in management is to keep the feet dry.

Patient Management

Juvenile plantar dermatosis tends to flare in the summer and improve with cooler temperatures, although some authors disagree with seasonal variability. Winter flares can be associated with chronically damp insulated winter boots worn by children. These children should be encouraged to remove damp socks and footwear immediately after returning home, apply a thick emollient to the soles of the feet, and put on a clean dry set of socks.

Management should focus on lifestyle modifications by encouraging patients to keep feet dry and wear ventilated footwear.

This condition typically resolves by puberty and rarely occurs in adults. Follow-up can be performed on an as-needed basis.

Unusual Clinical Scenarios to Consider in Patient Management

If patients fail to respond to the above therapeutic measures, alternative diagnoses such as atopic dermatitis, psoriasis, and tinea pedis, etc. should be considered.

What is the Evidence?

Ashton, RE, Griffiths, A. “Juvenile plantar dermatosis—atopy or footwear?”. Clin Exp Dermatol. vol. 11. 1986. pp. 529-34. (A prospective study of 250 children with juvenile plantar dermatosis in Liverpool, London. All children were patch tested, and only 9% had positive patch test profiles, suggesting that an allergic contact dermatitis was the unlikely cause of this condition. Compared to a control group of 172 children, patients with juvenile plantar dermatosis had a higher incidence of atopy [61%] in either their personal or immediate family history.)

Ashton, RE, Jones, RR, Griffiths, A. “Juvenile plantar dermatosis”. A clinicopathologic study. Arch Dermatol. vol. 121. 1985. pp. 225-8. (A case series of fifty-six patients [age 4 to 15 years] with juvenile plantar dermatosis reported the following sites of involvement: plantar big toe [93%], ball of foot [77%], flexural underside of toes [50%], and heel [23%], as well as a lesser involvement of the instep and dorsum toes. Histopathic features of juvenile plantar dermatosis included uniform parakeratosis and psorasiform acanthosis with focal loss of the granular cell layer.Additional epidermal changes were spongiosis, spongiotic vesiculation, paranuclear vacuolization of epidermal keratinocytes, and inflammation around the acrosyringium. Dermal infiltrates around the sweat ducts near the entry into the epidermis were also seen. These authors proposed that pathophysiologic mechanisms for juvenile plantar dermatosis were related to eczematous changes and disordered sweating.)

Enta, T. “Peridigital dermatitis in children”. Cutis. vol. 10. 1972. pp. 325-8. (One of the first references to juvenile plantar dermatosis in Canada.)

Graham, RM, Verbov, JL, Vickers, CF. “Juvenile plantar dermatosis”. Clin Exp Dermatol. vol. 12. 1987. pp. 468-9. (A review of ninety-eight patients [mean age 5.5 years old at presentation] with juvenile plantar dermatosis in Merseyside, London conducted over a 10-year period. There was a higher incidence of juvenile plantar dermatosis with atopic dermatitis, although it was not a unique manifestation of atopic dermatitis. These authors proposed that juvenile plantar dermatosis be classified as a form of irritant contact dermatitis related to increased plantar humidity and friction.)

Jones, SK, English, JS, Forsyth, A, Mackie, RM. “Juvenile plantar dermatosis—an 8-year follow-up of 102 patients”. Clin Exp Dermatol. vol. 12. 1987. pp. 5-7. (A prospective cohort study of 50 of 102 patients originally reported by Mackie & Husain [1976]. In these patients, mean onset , duration, and remission ages were 7.3 years, 8.4 years, and 14.3 years respectively. Patients also had a higher prevalence of atopy in their personal history [fifteen patients, 30%] and family history [six patients, 12%].)

Lachapelle, JM, Tennstedt, D. “Juvenile plantar dermatosis: a report of 80 cases”. Ann J Ind Med . vol. 8. 1985. pp. 291-5. (A case series of eighty patients with juvenile plantar dermatosis. Involved sites included the plantar big toe [eighty patients, 100%], forefoot [seventy patients, 87.5%], heels [seven patients, 8.7%], and palms [three patients, 3.7%]. The most frequently reported symptom was a burning sensation from fissuring [twenty-eight patients, 35%], but less commonly itch [five patients, 6.2%].)A history of atopy was present in personal history [eighteen patients, 22.5%], first-degree relative family history [forty-three patients, 53.7%], and both personal and family history [twelve patients, 15%]. The condition was worse in the winter for thirty-seven patients [46.2%], worse in the summer for seven patients [8.7%], and there was no reported seasonal variability in thirty-six patients [45%].)

Mackie, RM, Husain, SL. “Juvenile plantar dermatosis: a new entity?”. Clin Exp Dermatol. vol. 1. 1976. pp. 253-60. (These authors studied 102 school-aged children previously reported by Moller [1972] and Schultz and Zachariae [1972], and coined the term “juvenile plantar dermatosis” for a condition presenting as scaling, fissuring, and burning of the feet. There was no reported association with seasonal variation or atopy.)

Moller, H. “Atopic winter feet in children”. Acta Derm Venereol. vol. 52. 1972. pp. 401-5. (One of the first references to juvenile plantar dermatosis in Europe.)

Shipley, DR, Kennedy, CT. “Juvenile plantar dermatosis responding to topical tacrolimus ointment”. Clin Exp Dermatol. vol. 31. 2006. pp. 453-4. (A case report of an 8-year-old boy successfully treated for juvenile plantar dermatosis with tacrolimus 0.1% ointment twice daily and a topical emollient for four weeks.)