**3.1.3 Lip-licker's dermatitis**

Another relatively common form of irritant dermatitis in children is lip-licker's dermatitis. This presents as erythematous, scaly, thin plaques in a perioral distribution. Characteristically, the vermillion border is involved. It is caused by habitual licking of the lips and skin around the mouth and the irritant in this case is saliva. Atopy, wind and cold weather are predisposing factors. It is managed well with behavioral modification and topical emollients (i.e. petrolatum) acting as barriers from saliva. This entity should be differentiated from perioral dermatitis, which is an eruption of pink scaly papules that generally spares the skin involving the vermillion (Leung & Robson, 2005).

## **3.2 Allergic contact dermatitis**

As mentioned previously, the diagnosis of allergic dermatitis is more frequently being made in children. Tables 1 and 2 list the most common allergens detected in a series of investigations. A recent review evaluates 49 studies, most of which included symptomatic patients, finding the five most common allergens to be nickel sulfate, ammonium persulfate, gold sodium thiosulfate, thimerosal and toluene-2,5-diamine (Bonitsis et al., 2011). Table 3 provides prevalence rates of common allergens.


Table 3. Prevalence of Common Allergens in Selected Populations
