Atopic individuals are predisposed to skin infections because of a compromised physical barrier , coupled with diminished immune recognition and impaired antimicrobial peptide production .

AD follows a relapsing course and is associated with elevated serum immunoglobulin ( IgE ) levels and a personal or family history of type I allergies , allergic rhinitis , and asthma . Most patients improve in summer and are worse in winter .

RISK FACTORS According to the updated American Academy of Dermatology guideline , two risk factors appear to be consistently and strongly associated with the development of atopic dermatitis : A family history of atopy and a loss of function mutations in the filaggrin ( FLG ) gene .

Approximately 70 % of AD patients have a positive family history of atopic diseases . The odds of developing AD are two- to three-fold higher in children with one atopic parent , and this increases to three- to five-fold if both parents are atopic .

TREATMENT The goals of treatment are to reduce symptoms ( pruritus and dermatitis ), prevent exacerbations , and minimise therapeutic risks . Standard treatment modalities for the management of these patients are centered around the use of topical anti-inflammatory preparations and moisturisation of the skin , but patients with severe disease may require phototherapy or systemic treatment .

Topical agents include topical

corticosteroids ( TCS ), calcineurin inhibitors ( TCI ), antimicrobials and antiseptics and antihistamines .

TOPICAL CORTICOSTEROIDS Topical corticosteroids ( TCS ) have been used to treat AD for more than 60 years . TCS are used in the management of AD in both adults and children and are the mainstay of antiinflammatory therapy .

TCSs are used for both active inflammatory disease and for prevention of relapses . They are typically introduced into the treatment regimen after failure of lesions to respond to good skin care and regular use of moisturisers alone .

TCS are grouped into seven classes , from very low / lowest potency ( VII ) to very high potency ( I ), based on vasoconstriction assays . TCSs are recommended for AD-affected individuals who have failed to respond to good skin care and regular use of emollients alone .

A variety of factors should be considered when choosing a particular topical corticosteroid for the treatment of AD , including patient age , areas of the body to which the medication will be applied , and other patient factors such as degree of xerosis , patient preference , and cost of medication .

Twice-daily application of corticosteroids is generally recommended for the treatment of AD , however , evidence suggests that once-daily application of some corticosteroids may be sufficient .

Proactive , intermittent use of TCS as maintenance therapy ( one to two times weekly ) on areas that commonly flare is recommended to help prevent

relapses and is more effective than use of emollients alone .

No universal standard exists for quantity of application , although suggested methods include use of the adult fingertip unit ( the amount from the distal interphalangeal joint to the fingertip , or approximately 0.5g , being applied over an area equal to two adult palms ), following the rule of nines that measures the percent affected area , and use of charts that propose amounts based on patient age and body site .

Children have a proportionately greater body surface area to weight ratio , and as a result , have a higher degree of absorption for the same amount applied . But during significant acute flares , the use of mid- or higherpotency TCS for short courses may be appropriate to gain rapid control of symptoms , even in children .

However , for long-term management , the least-potent corticosteroid that is effective should be used to minimise the risk of adverse effects .

Greater caution regarding TCS potency is also needed when treating thin skin sites ( e . g . face , neck , and other skin folds ), where there is greater penetration and higher likelihood for systemic absorption . It is important to monitor quantities of TCS used over time , which may impact efficacy and safety .

TOPICAL CALCINEURIN INHIBITORS

Topical calcineurin inhibitors ( TCI ) are a second class of anti-inflammatory therapy introduced in 2000 . They are naturally produced by Streptomyces bacteria and inhibit calcineurindependent

T-cell activation , blocking the production of proinflammatory cytokines and mediators of the AD inflammatory reaction .

They have also been demonstrated to affect mast cell activation , and tacrolimus decreases both the number and costimulatory ability of epidermal dendritic cells .

Two TCIs are available , topical tacrolimus ointment ( 0.03 % and 0.1 % strengths ) and pimecrolimus cream ( 1 % strength ). Both agents have been shown to be more effective than vehicle in short-term ( three to 12 weeks ) and long-term ( up to 12 months ) studies in adults and children with active disease .

Physician global evaluation scores showed decline , as did the percent body surface area involved and patient evaluation of symptoms and signs of disease . Tacrolimus is approved for moderate to severe disease , whereas pimecrolimus is indicated for mild to moderate AD , and six-week comparative studies support a greater effect for tacrolimus over this time period for all AD severities .

In the US , TCIs are approved as second-line therapy for the short-term and non-continuous chronic treatment of AD in non-immunocompromised individuals who have failed to respond adequately to other topical prescription treatments for AD , or when those treatments are not advisable .

TCIs have the benefit of not carrying risk for cutaneous atrophy , with little negative effect on collagen synthesis and skin thickness . TCI can therefore be used as steroid-sparing agents and long-term studies .

References available on request .