More than ugg(ly) feet

March 1, 2015

Clinical Vignette

A 6-year-old girl with peeling soles is your first urgent patient of the day (fig 1). Although the peeling is not usually symptomatic, her feet become cracked, fissured, tender, and occasionally infected during the middle of the winter and summer when the eruption is at the worst. She is in the midst of her summer flare, when she can only wear her soft loose-fitting Uggs, and her mother won’t leave the office until you have the answer! What's he diagnosis?

Diagnosis and Clinical Presentation

Juvenile palmar-plantar dermatosis (JPD), affectionately known as sweaty sock syndrome, is a common dermatosis of infancy and childhood characterized by asymptomatic symmetrical, red, glazed, smooth appearance of the anterior surface of the soles and sometimes the palms (1). The dermatitis usually develops in the late fall or winter and involves primarily the distal aspects of the soles and toes with sparing of the interdigital spaces (1,2). The pink, scaly patches may crack and fissure and disrupt normal epidermal skin markings (1). Although most eruptions are not symptomatic, cracking and fissuring can cause pain with movement and secondary infection occurs occasionally.

Epidemiology and pathogenesis

The cause of juvenile palmar-plantar dermatosis is unknown, but repeated wetting and drying of the skin and resultant swelling and shrinkage of the stratum corneum as well as frictional trauma are all postulated contributing factors (1-4) JPD occurs most commonly in the winter when children wear occlusive athletic shoes during the day and go barefoot in dry forced air heated homes during the night. This phenomenon also occurs during the summer when the humidity is high outdoors and feet are immersed swimming pools followed by drying at night in dry air conditioned homes.

Differential Diagnosis

The differential diagnosis for juvenile JPD includes allergic/shoe contact dermatitis, tinea pedis, chronic atopic dermatitis, palmoplantar psoriasis, and pityriasis rubra pularis. (fig. 2) Unlike JPD, allergic contact dermatitis of the feet tends to involve the dorsum of the feet and often arises due to allergy to rubber components, chromates, or adhesives (1-4). JPD can be distinguished from tinea pedis by a negative KOH scraping and culture. Moreover, tinea pedis tends to involve the web spaces of the feet, particularly the fourth web space, followed by the instep.1 Psoriatic plaques are usually thicker than the scaling seen in JPD, and most psoriatics willl demonstrate lesions on the elbows, knees, scalp, and/or sacrum. Pityriasis rubra pilaris presents with a salmon colored thick scaly palms and soles and like psoriasis less likely to be confined to the feet.

Treatment

As the repeated wetting and drying of the skin appears to contribute to the development of juvenile palmar-plantar dermatosis, measures that keep the skin persistently moist of dry will interrup this cycle. Treatment should include use of cotton socks, avoidance of occlusive footwear, frequent sock changes and footwear rotation (1-3). Liberal use of emollients and, in occasionally topical steroids when there is a superimposed contact irritant component may result in rapid improvement. Antibiotics may be necessary for secondary infection.1 In some children the condition may improve during the summer with the use of open footwear and it often disappears in adolescence (3).

Conclusion

Sweaty sock syndrome should be considered in any child who presents with a palmar and/or plantar dermatosis with involvement of trauma exposed surfaces and sparing of web spaces.

References

  1. Paller AS, Mancini AJ: Hurwitz Clinical Pediatric Dermatology: A textbook of skin disorders of childhood and adolescence. Elsevier Saunders. 2006; 70, 72-74, 78-79.
  2. Guenst BJ: Common pediatric foot dermatoses. J Pediatr Health Care. 1999; 13(2): 68-71.
  3. Cohen BA: Pediatric Dermatology, 3rd Edition, Elsevier Mosby. 2005; 67-77, 85-86, 93-94.
  4. Shackelford KE, Belsito DV. The Etiology of allergic-appearing foot dermatitis: A 5-year retrospective study. J Am Acad Dermatol. 2002: 47(5):715-721.

Diagnosis and Clinical Presentation Tags

Pattern

Pigmentation

Anatomic Depth