Acute photosensitivity reaction in<unk> .<unk>  usually presents in childhood with the most common mode of presentation as acute photosensitivity of the skin. It affects areas exposed to the sun and tends to be intractable. A few minutes of exposure to the sun induces pruritus, erythema, swelling and pain. Longer periods of exposure may induce second degree burns. After repetitive exposure, patients may present with lichenification, hypopigmentation, hyperpigmentation and scarring of the skin.<unk>  usually first presents in childhood, and most often affects the face and the upper surfaces of the arms, hands, and feet and the exposed surfaces of the legs. Most patients, if the<unk>  is not as severe, manifest symptoms with onset of puberty when the male and female hormone levels elevate during sexual development and maintenance. More severe<unk>  can manifest in infancy.<unk>  can be triggered through exposure to sun even though the patient is behind glass. Even the UV emissions from arc welding with the use of full protective mask have been known to trigger<unk> .<unk>  can also manifest between the ages of 3 and 6. Prolonged exposure to the sun can lead to edema of the hands, face, and feet, rarely with blistering and petechiae. Skin thickening can sometimes occur over time. People with<unk>  are also at increased risk to develop gallstones. One study has noted that<unk>  patients suffer from vitamin D deficiency. Liver failure<unk>  accumulates to toxic levels in the liver in 5–20% of<unk>  patients, leading to liver failure. The spectrum of hepatobiliary disease associated with<unk>  is wide. It includes cholelithiasis, mild parenchymal liver disease, progressive hepatocellular disease and end-stage liver disease. A lack of diagnostic markers for liver failure makes it difficult to predict which patients may experience liver failure, and the mechanism of liver failure is poorly understood. A retrospective European study identified 31<unk>  patients receiving a liver transplant between 1983 and 2008, with phototoxic reactions in 25% of patients who were unprotected by surgical light filters. The same study noted a 69% recurrence of the disease in the grafted organ. Five UK liver transplants for<unk>  have been identified between 1987 and 2009. Frequent liver testing is recommended in<unk>  patients where no effective therapy has been identified to manage liver failure to date. Pregnancy<unk>  photosensitivity symptoms are reported to lessen in some female patients during pregnancy and menstruation, although this phenomenon is not consistent, and the mechanism is not understood.
Erythropoietic protoporphyria
Xeroderma pigmentosum
Pseudoporphyria
Harderoporphyria
Thalassemia
Scurvy
Hemoglobinemia
Megavitamin-B6 syndrome