Both chronic actinic dermatitis and contact dermatitis can give rise to chronic eczematous appearance, particularly on the face. They may both respond to emollients and topical steroids, but long-term effective management consists of elucidating the cause and taking action to avoid the offending agent. Thus correct treatment is quite different – patch testing is the only way of obtaining an accurate assessment of cause.
Chronic actinic dermatitis
• Affects areas exposed to light
• Initially sparing of light-protected areas occurs, such as on upper lids, under chin and behind ears, and those areas covered by clothing – involvement of hands, forearms and back of neck very suggestive
• May be later generalisation of eczematous rash
• May arise in normal skin or following endogenous eczema or allergic contact dermatitis
• Severely pruritic and lichenified
• Photosensitive to visible or UV light
• Particularly affects elderly males.
Treatment
• Broad-spectrum sunscreen
• Physical protection from sunlight
• Topical steroids are used and occasionally systemic steroids and steroid-sparing agents may be necessary (azothiaprine)
• Patients may also have multiple contact allergies and it will be important for these patients to avoid offending allergens.
Airborne allergic contact dermatitis
• Typically confined to exposed surfaces of hands, arms, face and neck
• Affects upper eyelids, anterior neck and behind the ears
• Dry, lichenified or vesicular eruption occurs in exposed areas
• Causative agents include pollens, ragweed, sawdust (gentleman in bottom photo had been working with iroko – a hardwood from West Africa), airborne household sprays, epoxy resin, composite plants and chrysanthemums.
Treatment
• Offending allergens should be identified by patch testing and avoided
• Topical steroids of appropriate strength for site – such as Betnovate for body, Eumovate for face – and emollients need to be applied.
Dr Andy Jordan is a GP and hospital practitioner in dermatology in Chesham, Buckinghamshire