- Photodermatoses – skin diseases that develop due to light exposure
- Photodermatoses of unknown origin
- Solar dermatitis = sunburn
- UVB radiation causes apoptosis of keratinocytes -> release of inflammatory cytokines
- Clinical features
- Pruritus, pain
- Erythema, oedema
- Blisters (severe)
- Treatment
- Wet compress
- Cooling ointments
- Topical steroids
- Polymorphous light eruption (PLE)
- Chronic disease
- In adult females
- Most common photodermatitis
- Clinical features
- Itching, burning erythema
- Malaise, headache
- Solar urticaria
- Rare
- Type I hypersensitivity
- Urtica at site of sun exposure
- Actinic prurigo
- Chronic actinic dermatitis
- Photodermatoses of known origin
- Phototoxic reactions
- Photoallergic reactions
- Diagnosis
- Photo-patch test
- UVA applied, then patch
- Read immediately, then at 24, 48, 72 hours
- Photo-provocation test
- Differentiate between solar urticaria, chronic actinic dermatitis, polymorphous light eruption, SLE
- Treatment
- Photohardening
- Photoprotection