‘Eczema’ is an umbrella term for polymorphic, pruritic skin conditions caused by a non-infectious inflammation of the skin. It is caused by intrinsic and / or environmental factors. ‘Atopic dermatitis (eczema)’ is a type of eczema with skin abnormalities in characteristic, age-dependent locations and an atopic
constitution. A characteristic feature of atopic eczema is an innately disturbed barrier function of the skin caused by genetic defects in the protein filaggrin, resulting in dry skin. The atopic constitution involves the predisposition to develop IgE mediated conditions, such as eczema, asthma and allergic rhinitis
and is often accompanied by elevated levels of immunoglobulin E (IgE).

Dry skin and an intense itch are the most prominent signs of atopic dermatitis. Presentation varies largely and depends on the patient’s age, ethnicity and disease activity. Characteristic acute lesions are erythematous papules and (mainly in young children) vesicles with exudation and crusting. Longer existing lesions present as dry, scaly or excoriated papules and (mainly in adults) as skin thickening from chronic scratching (lichenification).

In young children, atopic dermatitis typically presents on the extensor side of arms and legs and cheeks or scalp. In older children, adolescents and adults, plaques present more typically on the flexor surfaces (e.g. in knees, elbows, wrists) and they are more localised in adults.

Atopic dermatitis occurs mainly in children, with the very youngest (under one year of age) most commonly affected. Generally, atopic dermatitis presents before the age of five, and most affected children (80%) are free of symptoms by the age of 15. In underfive age groups, atopic dermatitis is by far the most common type of eczema.

Atopic dermatitis is a chronic skin disease, in which symptom-free periods often alternate with exacerbations. Factors that may aggravate the condition are transpiration, warm or cold temperatures, rough textile fibres (e.g. wool), illness, stress, soap, shampoo and cleaning products.

The diagnosis is made clinically, based on the history, appearance and distribution of skin lesions taking the patient’s age into account. Additional investigation is rarely needed but may be helpful when contact / allergic dermatitis or a food allergy are suspected.

Scratching aggravates dermatitis and should be avoided. Nails are best kept short. Bathing should be short, using lukewarm water and non-frequent. The use of emollients to increase the hydration of the skin and to reduce itch and irritation is the basis of the treatment, even when skin eruptions are minimal or absent. The personal preference of the patient or their parents is important in choosing which type of emollient to use. In addition, corticosteroids for topical use are often needed. They suppress the inflammation and reduce itching. Topical corticosteroids are categorised in four classes and the class of corticosteroid prescribed depends on the severity of the eczema, its effect, and the frequency of exacerbations. For moderate eczema, class i is advised, which can be replaced by class ii if the effects are insufficient. Class iii is advised for severe atopic dermatitis. Patients should be informed about how to apply creams or ointments. Referral to the dermatologist is appropriate if the response to treatment is insufficient or when the use of corticosteroids cannot be phased out.

In ICPC-2, atopic dermatitis is recorded as S87. Seborrheic dermatitis (S86) and other forms of dermatitis (S88) are recorded separately within ICPC-2.

Atopic dermatitis has an incidence of 10.2 per 1000 patient years (10.9 in women and 9.6 in men), meaning there are 10 new diagnoses of atopic dermatitis in a practice with 1000 patients in a year. Atopic dermatitis is mostly diagnosed in young children (0-4 years), with an incidence of 52.7 per 1000 patient years in this age group (54.8 for boys and 50.5 for girls per 1000 patient years). Link/Figure 1

The prevalence of atopic dermatitis is 32.1 per 1000 patient years. Link/Figure 2

Again, prevalence is highest among the youngest children, with a prevalence of 103.4 per 1000 patient years in the age group 0-4 (108.7 for boys and 97.9 for girls), meaning that one out of ten children under the age of five presents to the GP with atopic dermatitis each year. For this age group, atopic dermatitis is the fourth most common condition presented to the GP, after acute upper respiratory tract infection, acute otitis media and fever. Link/Figure 3 In all other age groups, the prevalence is higher among female than among male patients, especially for those between 15 and 44 years of age.

The higher prevalence compared to incidence indicates that atopic dermatitis is a chronic condition, generally requiring GP attention over the course of several years. Incidence and prevalence have increased slightly since 2014. We do not have an obvious explanation for this trend. An increasing trend of incidence and prevalence of atopic dermatitis has been reported in the last few decades across several continents.

The two most common initial reasons for encounter (RFE) for atopic dermatitis are ‘atopic dermatitis’ (S87) and ‘rash localised’ (S06), both of which account for 28% of all RFEs. This is followed by pruritus (itch, S02), in 9%, a request for medication (*50), in 7% of episodes, and a request to check the skin (*31) in 5%. Link/Table 4 The common presentation of ‘atopic dermatitis’ as an initial RFE demonstrates that many patients or their parents recognise the skin abnormalities as atopic dermatitis (eczema). Prominent differences in RFEs among different age or sex groups are largely absent.

By far the most common intervention for episodes of atopic dermatitis is the prescription of medication, occurring in 91% of all episodes in one year. Link/Table 5 This concerns mainly corticosteroids for topical use, prescribed in 69% of episodes, and emollients and protectives, prescribed in 47% of episodes of atopic dermatitis per year. Link/Table 6 Five-character specification of the ATC code demonstrates that prescribed corticosteroids concern mostly low potency and moderate potency corticosteroids (group i and ii), both of which are prescribed in 31% of all episodes each. The more potent corticosteroids from group iii and iv are prescribed in 15% and 3% of episodes, respectively. Link/Table 7 Sometimes, other medication classes are prescribed, e.g. antihistamines, antifungals or antibiotics for topical use, paraffin / fat products, agents such as tacrolimus / pimecrolimus and tars. Note that patients may receive several prescriptions for their eczema.

In children, emollients and protectives are prescribed more frequently (in 58% and 57% of episodes in the age groups 0-4 and 5-14, respectively) than in older age groups. When corticosteroids are prescribed to young children (age 0-4), the preference for less potent corticosteroids is clear: group i, ii and iii were prescribed in 52%, 23% and 2% of episodes, respectively. Link/Table 8 To a lesser extent, similar patterns are observed in children aged 5-14. Link/Table 9

Prescriptions of emollients, in 47% of episodes, and across all age groups, may seem relatively low, since this is the cornerstone in the treatment of atopic dermatitis. This can be explained by the fact that this medication can be bought over the counter without a doctor’s prescription. All prescribed medication for children is fully reimbursed by health insurance (i.e. free of a personal contribution), probably explaining the higher prescription rates of emollients among children.

In only 6% of episodes of atopic dermatitis, a specialist referral is made to a dermatologist or, occasionally, to an allergologist. Link/Table 10 Primary care referrals for atopic dermatitis (to the dietician) are rare. Link/Table 11

Dutch guideline: https://richtlijnen.nhg.org/standaarden/eczeem#volledige-tekst (2014)

Howe W. Atopic dermatitis (eczema): Pathogenesis, clinical manifestations, and diagnosis. In: UpToDate, Dellavalle RP, Levy ML, Fowler J, Corona R (Eds), UpToDate, Waltham, MA, 2023

Howe W, Paller AS, Butala S. Treatment of atopic dermatitis (eczema). In: UpToDate, Dellavalle RP, Levy ML, Fowler J, Corona R (Eds), UpToDate, Waltham, MA, 2023