الفهرس 
introductionOnly 14 pages are availabe for public view
 |  | from | 139 |  |  |
| | | from | 139 | | |
Abstract
Atopic dermatitis is the commonest chronic cutaneous disease of childhood in the
first years of life.It is an eczematous highly pruritic chronic inflammatory relapsing
skin disease. Its presentation varies from an acute eczematous relapsing eruption in
early life to a characteristic lichenified dermatitis in older patients. It often occurs in
people with personal or family history of other atopic disease as bronchial asthma,
rhinitis, and hay fever.
The role of vitamin D in calcium homeostasis has been well recognized, studies
have identified additional influences of vitamin D on the immune system, and several
lines of evidence suggest a possible influence of vitamin D on prevalence of allergic
diseases.
Staphylococcus aureus is believed to play a significant role in the pathogenesis
of atopic dermatitis,colonization with S. aureus is the most common skin infection in
AD (90% of patients compared to 5% of normal individuals) and occurs on both
lesional and, to a lesser extent, nonlesional AD skin.
IgE elevation on peripheral eosinophilia are Th2 polarity indicators,
characteristic in atopic patients, suggesting that Th2 cytokines can favor S. aureus
colonization of the skin. In a proportion of AD patients who respond poorly to antiinflammatory
treatment, persistent S. aureus colonization is associated with higher
total IgE levels suggesting that IgE may contribute to an increased susceptibility to
infection.
vitamin D has been shown to induce cathelicidin expression in
keratinocytes,that enhances antimicrobial activity against S. aureus.
The aim of this study was to investigate serum level of 25(OH)D and
specific IgE to Staphylococcus aureus in children with AD and their effect on the
severity of the disease.
Thirty patients were enrolled in the study (18 males and 12 females), their ages
ranged from 1to 14 years. Complete history taking,dermatological and general
examination, diagnosis as having AD by fulfilling the United Kingdom Working Party
diagnostic criteria for AD, disease severity determination by SCORAD index and
measurement of 25-hydroxy vitamin D and specific IgE to Staphylococcus aureus in
the sera of the patients were performed. Twenty age and sex matched normal control
subjects were also included in the study.
The mean value of 25(OH)D was significantly lower in AD patients group
compared to control group and (66.7 %) of the AD patients had insufficient or
deficient vitamin D, suggesting a possible role of vitamin D deficiency in the
pathogenesis and exacerbation of AD.
In this study an inverse correlation between serum concentrations of 25(OH)D
and severity of disease was found .The present study showed that patients with mild
AD had significantly higher levels of vitamin D than patients with moderate and
severe AD.
The median values of specific IgE to Staphylococcus aureus increased in AD
patients than in controls. There was a significant correlation between specific IgE to
Staphylococcus aureus and the severity of AD.
There was a significant correlation between vitamin D and specific IgE to
Staphylococcus aureus, it was found that there is an increased prevalence of patients
who were sensitive to Staphylococcus aureus in children with insufficient or deficient
levels of 25(OH)D.
In conclusion, vitamin D may be insufficient or deficient in a subset of atopic
dermatitis children especially those with moderate and severe disease. Our data,
showing a correlation between vitamin D deficiency and severity of AD in children, a
significant correlation between specific IgE to Staphylococcus aureus and the
severity of AD and a significant correlation between vitamin D and specific IgE to
Staphylococcus aureus.