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* How can GPs decide the importance of light in the patient's skin condition? * How should polymorphic light eruption be managed in practice? * What is the natural history [...]

A boy, aged 13, was brought to me by his mother and a friend, complaining of pains in his arms and legs, and inability to move his hands and feet. [...]

Chronic actinic dermatitis, as a single syndrome, has been suggested to include actinic reticuloid and photosensitive eczema. Actinic reticuloid is a chronic, severe skin disorder (without apparent inflammation) which occurs most often in elderly men, affecting sun-exposed skin. It is often confused with T-cell lymphoma, but actinic reticuloid has a very low T cell helper/suppressor ratio. Photosensitive eczema has an eczematous appearance and occurs at lower levels of UVA radiation (under 340 nm). Due to reports of cases of photosensitive eczema at greater than 340 nm and cases of actinic reticuloid which seemed to progress to photosensitive eczema, the unifying concept was proposed. Fourteen patients with chronic actinic dermatitis were studied to determine if a low T cell helper/suppressor ratio exists for chronic actinic dermatitis, and if so, is there a relationship between the T cell ratio and the severity of tissue change, or the extent of photosensitivity. Photobiologic, histologic and immunohistochemical investigations were completed. The tissues studied ranged from chronic dermatitis (inflammation) to cutaneous T cell lymphoma (abnormal lymphatic tissue growth). Immunohistological staining revealed that infiltrates from the epidermis into the dermis of the skin consisted mainly of T cell lymphocytes, and more severe tissue changes were associated with lower T cell helper/suppressor ratios. Levels of helper/suppressor T cells circulating in the blood were obtained for six patients; they were normal in five patients, and reduced in one patient. The spectrum of photobiologic abnormality did not appear to correlate with the severity of the tissue change, or variation of the T cell ratios. It was concluded that the predominance of suppressor cells, which delay anti-tumor responses in the body, may indicate a predisposition to lymphoma in patients with actinic reticuloid. (Consumer Summary produced by Reliance Medical Information, Inc.)

Photosensitivity can cause an itchy red rash on exposed skin that usually goes away within 24 hours after sun exposure. People with this condition should wear protective clothing and war sunscreen if they need to go outside. Phototherapy may also be recommended by a healthcare provider if prescription medicines such as antihistamine do not work.

The increased popularity of outdoor activities and leisure time are associated with a rise in the amount of exposure to the sun, and an increase in the prevalence of abnormal reactions to sunlight. Phototesting is used to diagnose these photosensitivity disorders and determine the range of sunlight that causes the abnormal reactions. The sun cannot be used as a light source because of its variable availability, intensity, and range. Artificial light sources, such as hot-quartz mercury-vapor, are used to diagnose photosensitivity disorders. The hot-quartz mercury-vapor lamp emits a light spectrum, or range, consisting of wavelengths up to 450 nanometers. The lamp is particularly useful in testing for photosensitivity disorders caused by light in the UVB range of ultraviolet light; it is more difficult to test for disorders caused by light in the UVA range. The hot-quartz mercury-vapor lamp was designed for delivering therapeutic doses of ultraviolet light to specific areas of the body, rather than for use in phototesting. A modification of the hot-quartz mercury-vapor lamp was developed, and is suitable for office-based phototesting. The modified lamp minimizes exposure of patient and personnel to potentially harmful light and reduces the risk of laboratory error due to light from other sources. In addition, the new lamp distinguishes between the roles of UVB and UVA ultraviolet light in causing photosensitivity disorders. Phototesting with the modified lamp was shown to be safe, easily performed, and readily accepted by both patients and personnel. (Consumer Summary produced by Reliance Medical Information, Inc.)

SNOWMASS, COLO. -- Photosensitivity diseases can often be confused with other dermatologic conditions, but a few key observations can often shed some light on a correct diagnosis, according to David [...]

DORADO, P.R. -- Diagnose the condition causing photosensitivity in a patient and rule out lupus and HIV infection to determine the appropriate management, Dr. Vincent A. DeLeo said at the [...]

HERSHEY, PA. -- Patch testing may help distinguish polymorphous light eruption from photoallergic/allergic contact dermatitis, Dr. Vincent A. DeLeo said at a meeting on contact dermatitis. His point was illustrated [...]