- Contact dermatitis is an inflammatory reaction to external agents that may be an irritant or allergen. Irritant contact dermatitis (ICD) is related to direct chemical or photochemical injury.
- In infants and children, ICD can be related to contact to bodily fluids eg urine or stool in diapers, or with saliva in lip licking esp during cold months or winter.
- Allergy contact dermatitis (ACD) is a delayed type of hypersensitivity induced by previous exposure and sensitization. Sensitization to contact allergens can occur as early as 6 months but it is rare in the first few months of life, increasing in prevalence with age.
- Most common causes of ACD in children are nickel, topical antibiotics, preservative chemicals, fragrances and rubber accelerators.
- Allergens must be considered as potential causes in cases of eyelid eczema, atopic cheilitis, hand and foot dermatitis, generalized eczema and even isolated flexural eruptions.
- Common allergen sources eg:
– Nickel in earrings (earlobe dermatitis),peri umbilical dermatitis from jean studs, belts
– Formaldehyde reactions eg formaldehyde releasing preservatives in baby wipes, shampoos and personal hygiene products
– Preservatives like methylisothiazolinone found in baby wipes, emollients and other products.
– Corticosteroid allergy is uncommon in children but should be suspected when an eruption flares and fails to improve with corticosteroids therapy.
See below pics for the potential causes of contact urticaria of hands and its many different manifestations.