Efficacy of Oral Supplementation of Probiotics in Children With Atopic Dermatitis

Atopic dermatitis (AD) is the common chronic inflammatory skin disease with relapsing courses that often start in infancy and childhood. It is characterized by erythema, itchy papules, occasionally vesicles (in infants), which may become excoriated and lichenified and have a typical flexural distribution. Atopy is defined as a "personal or familial tendency to produce immunoglobulin antibodies in response to even low doses of allergen, and associated with development of AD, asthma and rhinoconjunctivitis.The worldwide prevalence of AD is estimated to be 20% in children and 2-10% in adults. The incidence of AD has increased by 2 to 3 folds in past 3 decades in the industrialized countries and represents a major public health burden. According to the International Study of Asthma and Allergies in Childhood (ISAAC) phase 3, the prevalence of AD among the age group of 13 to 14 in Africa and Latin America was at 12-14% and 6-10% respectively. The Asian Pacific countries, the Eastern Mediterranean region and the Indian subcontinent, it was 3-6% among the same age groups (13-14 years). Whereas among 6 to 7 years children, for Asian Pacific countries, Africa and Latin America the prevalence of AD was around 10% and in Indian subcontinent and Eastern Mediterranean region, value was lower at 3-5%

In Nepal the frequency of AD in all age group was 2% as per a year hospital based study done by Singh S and Agrawal S et.al in 2012. (Unpublished data, on personal communication)

The pathogenesis of AD appears to result from interaction between various genetic and environmental factors. It is associated with skin barrier dysfunction and immune dysregulation. The barrier dysfunction is early feature of AD which may be a primary but may also be a secondary to skin inflammation. Lack of exposure to microbial stimuli in early life programs the immune system towards Th2-type allergic response as described by 'hygiene hypothesis'.In allergic disorders there is shift of the Th1/Th2 cytokine balance towards a Th2 response, and causes the release of Interleukin-4, interleukin-5 and interleukin-13 as well as Immunoglobulin E production.

The diagnosis of AD is mainly clinical as there is no specific test for AD. Diagnosis of AD is based on specific a criterion which includes patient's history, clinical presentations as well as family history. In 1980 Hanifin and Rajka proposed major and minor diagnostic criteria based on clinical symptoms of AD. Williams coordinated a UK working party to attempt to simplify and refine the criteria given by Hanifin and Rajka in 1994. Severity of disease is evaluated by using widely accepted SCORing Atopic Dermatitis (SCORAD), based on extent of area involved, severity of symptoms and intensity of the subjective symptoms of pruritus and sleep disturbances.The chronic and recurrent nature of AD negatively impacts the quality of life (QOL) of patients as well as their family members. The symptoms of AD limit patient's physical, psychosocial development and quality of sleep.

The main goals of treatment are to improve the skin barrier function and hydration, to suppress inflammation and to control microbial colonization. It can be achieved through emollients, topical corticosteroids and topical calcineurin inhibitor like tacrolimus. Oral drugs like corticosteroids, methotrexate and cyclosporine are reserved for severe cases.