Chronic actinic dermatitis vs contact dermatitis
GP and hospital practitioner Dr Andy Jordan completes his series on differentiating similar-looking skin conditions
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.
• 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.
• 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