The sunrays always make for a natural stimulation of our skin; phototherapy reproduces the benefits, while limiting the risks. Atopic dermatitis usually responds positively to treatment by narrow band UVB, with a significant reduction of itching already starting from the 6th to the 8 th exposure of a total cycle of 24-36 exposures, depending on the subject to be irradiated. Side effects in the long term are not known. The risk of skin carcinogenesis has never been established to be a result of treatment cycles where cumulated doses of radiation used are still lower than those of a sea summer holiday in our latitudes.
Atopy is a genetic predisposition towards an exaggerated skin or mucous response to a variety of environmental stimuli. The main phenomena of atopy are asthma, atopic rhinoconjunctivitis and atopic dermatitis.
Atopic dermatitis is a chronic skin disorder with exacerbations that initiate during infancy or childhood and that can persist into adulthood. Therefore stages of AD are divided into neonatal, child and adult.
The incidence of this disease has increased from 3 to 10-15% in the last 50 years because of the increased exposure to pollutants, household allergens and the decrease of breastfeeding. The overall incidence is currently estimated to be between 5-20% during childhood and between 2-10% in adulthood. Atopic dermatitis is persistent or has recurrence in 60% of individuals.
The etiology is based on genetic factors, although there is a large number of external factors that may alter its appearance. In 60% of cases of AD, a family history of atopy can be proven, in other words, if a parent has an atopic diathesis, there is a 60% chance that the children may be atopic. If both parents are atopic, the percentage increases to 80%. In a non-atopic family, the chances of having an atopic child are currently about 20%.
Atopic dermatitis, as mentioned, affects mainly children, but sometimes there are events that go on until adulthood, characterized by severe itching that settles primarily in skin folds (inner arms and legs, neck, eyes, hands etc.) It is a reaction mediated by the immune system, whose excesses unleash a real torment, especially at night, leaving those affected with a need to scratch that can lead as far as to skin abrasion.
The disorder most commonly associated with AD is dry skin that is scientifically known under the name of xerosis. In this condition there is an increase in transepidermal water loss because of an abnormal formation of the barrier function of the horny layer.
The following can also be associated with AD: ichthyosis vulgaris, keratosis pilaris, pityriasis alba, white dermographism, lichen spinulosus and infantile seborrheic dermatitis.
In addition, patients with AD are at greater risk of developing irritant contact dermatitis and to be sensitive to a variety of contact allergens, including corticosteroids and latex. Alopecia Areata is also more common in atopic individuals.
Seborrheic dermatitis usually occurs in adolescence or adulthood, localized on the face, especially at the edges of the nose, sometimes even on the shoulders, chest and scalp, with localized itching and exfoliation. It normally subsides within a few years, but sometimes it continues until adulthood and there are also cases of late onset, with episodes that are followed within a few weeks: periods of relative normality, almost quiescent, alternate with others where the exfoliation becomes more evident and episodes reoccur in a high frequency pattern.
The diagnosis is simple, just a skin examination, often it is the general practitioner that identifies the characteristics, as these are very typical of the disease and so are the locations as well.
The disease is considered to be of genetic predisposition by autoimmune triggering, therefore it is easily found at several members of the same family, given its exclusively hereditary means of transmission. It can as well remain in a latent state throughout an entire lifespan, surge along a rapid rise of the immune response or as well resolve completely with age. Cases exceeding 35-40 years of age are very seldom, mostly in women, with a tendency to dissipate during the first pregnancy. Increased itching is also often reported to appear during the last days before the period.The classical therapy consists in the use of topical corticosteroids, which offer virtually immediate relief. The latter are sometimes associated with oral antihistamines, but after a while the skin tends towards atrophiating, requiring higher doses of cortisone to obtain increasingly bland results.
During summertime, episodes of SD are fewer, thanks to the greater exposure to sunlight, which reduces the action of the immune system and limits the appearance: it is the base principle used to introduce new drugs (topical immunosuppressants) and phototherapy, the technique of choice in the treatment of SD, for its efficacy and reduced side effects and therefore suitable for long term use.
Narrowband UVB phototherapy has confirmed its effectiveness in the treatment of SD, both short and long term, even in children as young as six years.
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