Contact dermatitis

Any time a contact allergen is identified, the dermatologist or allergologist should give the patient the list of the sources of the substance to avoid, involving possible molecules that could cross-react. Determination of relevance is the most important task as not all positive reactions are relevant. Avoidance of irrelevant positive reactions will not lead to improvement.

Educate patients about the causative agent and how to avoid it, and also about which products are safe to use.

Advise patients to read product labels. Educate patients about cross-reacting allergens and alternative names for allergens.

Advise patients allergic to fragrance to use fragrance-free products. Products labelled 'unscented' may still contain fragrance in small concentrations to conceal the odour of other components.

Systemic contact dermatitis should also be discussed if patients are positive to allergens that could potentially elicit reactions when ingested such as nickel, cobalt, balsam of Peru, chromium, or gallates.