Allergic contact dermatitis in children is on the rise and closely associated with lifestyle changes. With increasing exposure to common allergens due to the popularity of jewelry, body paints, cosmetics etc., children are developing contact sensitivity very early on.

Prevalence

That children rarely contract a contact allergy is now a myth. In the last 10-20 years, contact allergy has become a challenge for pediatricians worldwide. Positive patch test results have registered a variant rate of 14.5% to 70% of cases, with clinical relevance in 20% to 92% of cases. This variance in the rates reported by different studies has made the prevalence of contact allergy in kids difficult to define. However, most studies have commonly concluded that allergic contact dermatitis occurs more in older children than younger ones and rate of incidence increases with age, as contact with allergens increases. Generally, by the age of 10, it is as frequent as in adults.

Diagnosis

The spread of eczematous lesions is a key indicator rather than the manifestation of specific lesions. A skin eruption that has an uncommon appearance or is confined to a particular skin location (face, feet etc.) should be screened for allergic contact.

The clinical appearances also have a major role to play in proper prognosis of the disease in kids. They typical forms are:

• Earlobe, neck, or sub-umbilical (below the belly button) skin eczema with nickel allergy (ear rings, jewellery, metal snaps on pants).
• Foot eruption including shoe dermatitis.
• Now-a-days a new kind of diaper dermatitis occurs due to rubber, chemicals or glues in disposable diapers.
• The ‘baboon syndrome’ (the term is derived as an association with the red gluteal region of the baboon), which is a systemic allergy in the flexural regions of the extremities, the buttocks, and the anogenital areas. Though rare, it occurs in children after systemic exposure to mercury, ampicillin, amoxycillin, nickel, erythromycin, heparin and food essence.
• Medication related aggravation of atopic dermatitis, during therapy of the same, might occur as a result of allergy to the ingredients of the preparation.

Patch tests in children

Patch testing is mainstay in the accurate diagnosis of contact allergy. Before a patch test, a medical history and screening could give an indication of allergens the child may be reactive to. However, one must patch test not only with probable allergens but also unknown ones as well. For instance, in one patient with eruptions on the areas of the soles that undergo maximum pressure, was initially diagnosed with allergic contact dermatitis from shoe linings or adhesives. But on testing, medication to contact allergy was found to be the real trigger.

There is considerable debate about the concentration of allergens to be used for patch testing in children. Initially, it was suggested that children be tested with a lower intensity of allergens than adults to avoid risk of too much skin irritability.

However, that might result in false-negative test outcomes. While some recommended that the concentration be half for nickel, rubber chemicals and formaldehyde, others suggested that it be suited to the age of the child and all positive patch reactions be repeated using the half intensity formula. However, nowadays the accepted practice is to test children with the same strength as used in adults.

A key disadvantage of patch testing in children is inadequate space on their small backs. This can be addressed by testing with a lesser number of series of allergens at a time.

Management

The first step for a proper management of this disease among children is to understand its earlier neglected childhood occurrence. Once that is clear here are a few points to remember:

• The patient’s medical history is a must.
• Details about the patient’s fashion, personal care and lifestyle preferences is vital.
• The recreational activities are also required. For instance, the source of dermatitis in a student was actually traced to her cellist teacher’s finger dermatitis and residue on the instrument strings that in turn was due to a chemical p-phenylendiamine.

This apart, one must be aware of the main triggers. They are:

• Jewellery that includes procedures like body piercing, ear piercing.
• Temporary tattoos that includes use of black henna mixtures, containing indigo, henna and chemical coloring agents such as p-phenylendiamine (PPD) and/or diaminotoluens.
• Natural remedies that includes herbal preparations and aromatic therapies.
• Vaccination that includes the mercury-based vaccine preservative thiomersal.
• Children’s cosmetics that includes fragrances.

Prevention and therapy

Since there is no standard therapeutic practice, avoiding the triggers is the standard means of prevention. There have been a number of legislations from time to time, which has reinforced the prevention process. They are:

• The Cosmetics Directive 76/768/EEC and its amendments: This deals with the safe use of cosmetics. A section of it concentrates on the prevention of contact dermatitis, with a chart of preservative ingredients of cosmetics, with their maximum permissible concentrations. However, it does not provide any data about the restrictions for children other than toxicological adversities.
• The EU Nickel Directive: It restricts the nickel component in some products.
• In 1992, the Danish Ministry of the Environment came up with a directive on how to avoid nickel contamination of the skin.

Moreover, since children come in contact with allergens at a very early age ways to avoid them should start off early and must involve the parents. Hence, parents should be extensively educated about common allergens.

Here are some tips:

• Paediatric detergents should be very gentle to avoid irritant dermatitis and chemically simple to avoid allergic dermatitis.
• Topical preparations for children should be not contain fragrances and preservatives.
• The dose of topical antibiotics should be limited during childhood in order to prevent the possibility of sensitization to some antibiotics and to prevent bacteria in children from becoming resilient to a drug early on.
• Ear piercing should not be allowed in kids under ten years of age.
• Parents should be educated about skin care during childhood. They must be made aware that ‘herbal’ does not mean preparations are absolutely safe.