Atopic dermatitis (AD) is characterised by a chronic, relapsing skin inflammation. The prevalence is high (estimated 15-30% for children and 2-10% for adults) and increasing worldwide. AD can affect all age groups from newborns to adults, but is far more prevalent among children. The clinical picture varies with age, but most of the patients are suffering from dry and red skin. Itch is the major symptom leading to sleep disturbances and impairment of quality of life.
Asthma, allergic rhinitis and food allergies very often present in AD patients, because of similar background. Most common food allergens are cow's milk, hen's egg, peanut, tree nuts, wheat, soy and shellfish. Allergic reactions to food allergens can present a immediate type (urticaria, angio-oedema, diarrhoea, coughing) and late phase reactions. Proper diagnosis and management of food allergy in AD patients is very important to avoid unnecessary, malnutrition or additional psychological stress.
The research interest in AD is high and is growing continuously. Those who are genetically predisposed and then exposed to environmental trigger factors may develop AD (gene-environment interaction). Major news piece in the puzzle of the pathogenesis is the discovery of the genetic mutation, suggesting AD as a skin barrier disorder. Today both epidermal barrier function and the immune system are considered as major targets for therapy.
Treatment options, especially in children, are limited in AD. According to the new understanding of the disease early and proactive strategies with emollients and appropriate skin care becoming more and more important in the disease management. This strategy can help to reduce the number of flares and when used in early infancy, to prevent the development of AD and other related atopic conditions ('atopic march').
The holistic approach
The holistic approach of managing children high risk for AD+ food allergy or patients with AD+ food allergy is necessary and integrates advice on diet, skin care, avoidance policy and treatment.
Prevention: dietary intervention from birth
The best way to prevent exposure to dietary allergens is breastfeeding. However, for infants not being breastfed, there is convincing and established evidence that feeding a partially hydrolysed infant formula significantly and lastingly reduces the risk if atopic dermatitis. A meta-analysis (Szajewska and Horvath) confirm that the use of a partially hydrolysed formula (NAN HA) compared to standard cow's milk formula (CMF) is effective in the prevention of atopic dermatitis in children with a positive history for allergy. Another meta-analysis (Alexander and Cabana) shows that NAN HA reduces the risk of AD during the first years of life by 45%, and that NAN HA has prolonged preventative effect of up to three years.
In addition, data from the follow-up of the German Infant Nutrition Intervention (GINI) study (RCT) - the world's largest allergy prevention study which includes more than 2,000 infants, until six years of life confirmed the long-term allergy preventative effect of NAN HA of AD until six years of age.
Exclusive breastfeeding should continue to be encouraged as a means of reducing atopic dermatitis, as well as to promote other health benefits. For infants with familial predisposition to allergy, the exclusive feeding of NAN HA during the first four-six months of life is recommended, as a means to reduce the risk of AD when there is no or insufficient breastmilk.
As there are as yet, no accurate means of predicting individual risk of allergy, even though the burden of allergic diseases to society is large enough to make the identification of newborns at risk, an important endeavour. The allergy-preventative effect in children without a family history of allergy has not yet been examined, but NAN HA is especially well tolerated, fulfils all that is required of an infant formula, making its use in the general population considered as a potentially effective health measure.
Integrating diet and topical intervention
- Parents of newborns and infants prone to food allergies and AD need specific education regarding skin care and diet in order to prevent these disorders. Atopic-prone skin is vulnerable and skin care products can lead to skin barrier damage and development of AD. This is the reason why hypoallergenic, non-irritant, fragrance-free products should be used in this population. Skin cleansing has to be gentle with mild surfactants. Skin hydration can be ensured with regular use of emollients, which reinforce the barrier and make it resistant against allergens, irritants and microbes.
- Parents of newborns and infants with food allergy and AD need specific education regarding treatment, skin care and diet in order to treat the disease.
Emollients should be considered as first-line therapy in the management of mild AD and should be used in conjunction with a bathing regimena that requires the use of a mild soap or body wash to minimise irritancy or potential fleare-ups.
Recent evidence has found that currently more than 50% of children with moderate to severe atopic dermatitis have a filaggrin gene mutation resulting in the decrease or total absence of filaggrin resulting in a significant decrease in the water content in the stratum corneum.
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