Juvenile plantar dermatosis

A smooth, shiny, glazed red surface over the forefoot and toe pulps, dry rather than weeping, with painful fissures. The skin looks varnished.

The erythema is largely lost, but this condition is unusually recognisable in darker skin because its defining quality is a surface property, not a colour: the glazed, shiny, varnished appearance of the weight-bearing forefoot reflects light and is visible across the Fitzpatrick range, and the fissures are visible and palpable. Look at the foot obliquely under good light for the sheen rather than looking for redness. NICE NG240 makes the general point that rashes can be hard to detect on brown, black or tanned skin. Looking at the foot obliquely under good light is this page's own practical advice, not NG240's. Expect post-inflammatory hyperpigmentation over the forefoot once the fissures settle; it is not residual disease. No skin-of-colour series specific to this condition was found.

• Shiny, glazed, dry surface over the weight-bearing forefoot - not moist, not macerated
• Toe clefts are spared, which is the discriminator from tinea pedis, where the clefts are the usual site
• Symmetrical and confined to pressure areas
• Painful fissures are the presenting complaint more often than the rash
• Worse with occlusive footwear, trainers and synthetic socks, and often worse in winter
• Usually settles spontaneously around puberty

• Contact dermatitis - allergic and irritant — The one to exclude. In a series of 389 children referred for patch testing, 52 had dermatitis confined to the feet, and allergic contact dermatitis from footwear was the commonest diagnosis at 44.2% - juvenile plantar dermatosis accounted for only 15.4%. Chromate, cobalt and rubber accelerators are the usual culprits
• Tinea corporis, cruris and pedis — Tinea pedis favours the toe clefts, which this condition spares, and is usually asymmetrical and macerated rather than glazed
• Atopic eczema and infected eczema — Accounted for 23.1% of foot-limited dermatitis in the same series; it is less confined to pressure areas and there are usually signs elsewhere
• Pompholyx — Also affects the feet, but with deep tense vesicles on the soles and sides of the toes rather than a glazed dry surface
• Psoriasis, including guttate — Palmoplantar psoriasis is also fissured and dry, but with thicker scale, a sharper edge and signs elsewhere

1. Check the toe clefts. Spared clefts with a glazed forefoot is the diagnosis; involved clefts points to tinea
2. Take the footwear history seriously and consider patch testing. The evidence says allergic contact dermatitis is nearly three times commoner than this condition among children referred with foot-limited dermatitis, so 'juvenile plantar dermatosis' should not be a label applied without that thought
3. Advise on footwear and socks: leather or breathable shoes, cotton socks, changing socks during the day, and alternating pairs of shoes so they dry
4. Treat with a greasy emollient used heavily, and a topical corticosteroid for inflamed fissured areas. Emollient is the mainstay
5. Treat painful fissures directly - they are what hurts and what stops the child walking or playing
6. Refer for patch testing where it is persistent, where it does not fit, or where the footwear history is suggestive

GP management with emollients and footwear advice. Refer to dermatology for patch testing where allergic contact dermatitis is suspected or where the condition persists despite good basic care.

• Ortiz-Salvador JM, Esteve-Martinez A, Garcia-Rabasco A, Subiabre-Ferrer D, Martinez-Leborans L, Zaragoza-Ninet V. Dermatitis of the foot: epidemiologic and clinical features in 389 children. Pediatr Dermatol 2017;34(5):535-9
• NICE NG240 - Meningitis (bacterial) and meningococcal disease: recognition, diagnosis and management. Recommendation 1.1.12: check all over the body (including nappy areas), check for petechiae in the conjunctivae, and note that rashes can be hard to detect on brown, black or tanned skin