**6. Clinical relevance**

Contact sensitization, however, does not necessarily equate with clinical diseases. Clinical relevance of allergic reactions on patch testing was determined according to the clinical history, type of dermatitis and the allergen concerned. Relevance of allergens should be determined for all patients with one or more positive reactions. Clinical relevance was confirmed if the allergen was found to be present in the patient's environment, the dermatitis corresponded to point(s) of contact with the allergen and the dermatitis significantly improved upon isolation of the allergen, or recurred with re-challenge (positive use test) (Jacob et al., 2008). Reported clinical relevance in children has been varied between 20% and 93% (Pevny et al., 1984b; Rademaker & Forsyth, 1989; Pambor et al., 1991; Stables, 1996; Mortz & Andersen, 1999).

Allergic Contact Dermatitis in Children 117

may explain the high rate of positive patch test reactions (Katsarou et al., 1996; Militello et al., 2006; Goossens & Morren, 2006; Milingou et al., 2010). Low clinical relevance along with sensitization rates is probably related to its presence in vaccines (Novák et al., 1986; Osawa et al., 1991; Lee et al., 2009). Recently, percentages of sensitization in children have increased from 2.3% (Barros et al., 1991) to 10% (Möller, 1997) due to iatrogenic sources (antiseptics, topical medications, thermometers and vaccines) and footwear (Novák et al., 1986; Osawa et

Neomycin, bacitracin and gentamycin are topical antibiotics with high rates of allergic contact sensitization in children (Heine et al., 2004; Seidenari et al., 2005; Jacob et al. 2008). Neomycin sulfate has remained second place in the most common culprits in ACD for close to 25 years (Spann et al., 2003; Lee et al., 2009). It is a topical antibiotic with multiple clinical indications, including use for superficial wounds or burns and can be found in many overthe-counter products in the US or Europe. It is also formulated in combinations with other antibiotics, antifungals or corticosteroids (Lee et al., 2009). Menezes de Pádua et al. (Menezes de Pádua et al., 2005) found 2.5% positive reactions to neomycin, while in 1.1%, ACD was

The market for cosmetic products specially formulated for children is expanding and usage of cosmetics being seen to increase in children. Consequently, one can expect cosmetics to become more important causes of ACD in children (Goossens et al., 2002). At least one cosmetic or cosmetic ingredient gave a positive reaction in 30% of the children investigated (Goossens et al., 2002; Goossens & Morren, 2006). Almost every ingredient may be responsible for cosmetic dermatitis (Goossens et al., 2002; Goossens & Morren, 2006). Fisher (Fisher, 1995) further stated that children often become allergic to cosmetics used by the mother or the person taking care of them. The localizations often involved seem to be the forehead and the cheeks, with perfume, lipstick, hairspray or nail lacquer as the responsible agents (Fisher 1995; Goossens et al., 2002; Buckley et al., 2003; Goossens & Morren, 2006). However, children often use cosmetic products themselves and this may not always be

The use of cosmetic products in babies and young children can cause perfume allergy (Fisher 1995; Goossens et al., 2002; Buckley et al., 2003; Goossens & Morren, 2006). A large numbers of perfumed products are marketed especially for children (Rastogi et al., 1999; Kohl et al., 2002). Fragrance allergy is increasingly common and even young children are exposed (Rastogi et al., 1999). Exposure is usually due to perfumes or to other aromatic topical products such as moisturizers or deodorants. Typical sites of involvement include face, neck and axillae, in addition to full systemic contact dermatitis (Tomar et al., 2005; Garg et al., 2009; Lee et al., 2009). Fragrance allergy is usually detected by patch testing to three mixtures of scented compounds: Fragrance Mix I, Fragrance Mix II and *Myroxylon pereirae* tree extract *(*Balsam of Peru). The rate of sensitization to fragrance appears to increase with age (Buckley et al., 2003; Lee et al., 2009). The *Myroxylon pereirae* tree extract

al., 1991; Militello et al., 2006; Goossens & Morren, 2006; Lee et al., 2009).

revealed immediately (Goossens et al., 2002; Goossens & Morren, 2006).

**7.3 Topical antibiotics** 

additionally diagnosed.

**7.4 Cosmetics allergens** 

**7.4.1 Fragrances** 
