Differential Diagnosis for Hypersensitivity to the Sun
- Single Most Likely Diagnosis
- Porphyria Cutanea Tarda (PCT): This condition is characterized by an abnormal sensitivity to sunlight, leading to blistering, scarring, and skin fragility. It's a common porphyria that presents with photosensitivity.
- Other Likely Diagnoses
- Systemic Lupus Erythematosus (SLE): A chronic autoimmune disease that can cause a range of symptoms, including sensitivity to sunlight, which can trigger or worsen skin rashes and other symptoms.
- Polymorphic Light Eruption (PMLE): The most common form of photodermatosis, characterized by an itchy, bumpy rash that appears after sun exposure.
- Actinic Prurigo: A rare condition that causes an itchy, blistering rash on sun-exposed areas, more common in individuals with a history of atopic dermatitis.
- Do Not Miss Diagnoses
- Xeroderma Pigmentosum: A rare genetic disorder where the body is unable to repair DNA damage caused by UV light, leading to severe sunburn, blistering, and a high risk of skin cancers.
- Erythropoietic Protoporphyria (EPP): A rare genetic disorder that causes severe burning pain after sun exposure due to the accumulation of protoporphyrin in the skin.
- Rare Diagnoses
- Solar Urticaria: A rare condition where hives or itchy wheals appear on sun-exposed skin, often within minutes of exposure.
- Chronic Actinic Dermatitis: A rare skin condition characterized by a persistent, itchy rash on sun-exposed areas, often seen in older adults.
- Hartnup Disease: A rare genetic disorder affecting amino acid transport, which can lead to a pellagra-like syndrome with photosensitivity among other symptoms.