Dr Paul Charlson provides 10 top tips on the diagnosis, treatment, and management of eczema in primary care

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Read this article to learn more about:

  • distinguishing eczema from other skin conditions
  • topical treatments and quantities that should be used based on the affected site
  • when it is appropriate to test children with eczema for food allergy.

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Eczema is a broad term and often used interchangeably with dermatitis. It affects 20% of children and 8% of adults in the UK. Between 2001 and 2005 the number of cases of eczema in England increased by 40%.2

The different forms of eczema can make for diagnostic confusion, but usually the diagnosis is not difficult and the treatment is similar.

Eczema can occur as a result of a profoundly disturbed epidermal barrier. It leads to dry skin because of a high transepidermal water loss and an enhanced penetration of irritant substances and allergens.3

The following tips are based on more than 10 years’ experience in community dermatology clinics; some are common diagnostic issues and others are management pitfalls.

1 Avoid confusion with psoriasis at diagnosis

Eczema can be confused with psoriasis but some key differences may make the diagnosis easier (see Table 1, below).

Table 1: Differences between eczema and psoriasis
FactorEczema4Psoriasis5
Definition of patches Ill-defined patches Well-defined patches
Profile Patches are not usually raised Patches are often raised
Surface Affects flexor surfaces usually Affects extensor surfaces usually
Natal cleft/umbilicus Not usually affected Often affected
Nails Irregular ridges Micro-pitting, onycholysis (separation of the nail from the nail bed), and salmon patches
Clinical/family history History of atopy—asthma, hay fever, and urticaria Family history of psoriasis

Sometimes it is difficult to identify which condition it is and there are crossover conditions known as eczema with psoriasiform features and parapsoriasis. If there is diagnostic uncertainty a second opinion and, sometimes, a skin biopsy are useful. This is preferable to treating the condition incorrectly, especially as potent steroids can cause tachyphylaxis (acute drug desensitisation) in psoriasis, and calcipotriol derivatives are expensive and not very effective in eczema. In all cases emollients are helpful.

2 Take a skin scraping to confirm discoid eczema or fungal infection

Eczema and fungal infections can sometimes be confused. At times the conditions coexist, creating further confusion. Look for a history of atopy, which makes the diagnosis of eczema more likely. Look for fungal infection in the patient’s toe webs, nails, and groin. Patches of discoid eczema are often more numerous and are less well defined at the edges with less central sparing (see Figure 1, below). They do not tend to grow from a small to a larger area over time.

Discoid eczema

Figure 1: Discoid eczema

Source: Image from DermNet NZ. Reproduced with permission

Further confusion occurs because potent steroids initially help fungal infections by reducing inflammation and altering their appearance (tinea incognito) and creams, such as those containing miconazole and hydrocortisone, have some effect on eczema. If the diagnosis is unclear, skin scrapings for mycology are useful and can be done in the GP setting in less than 3 minutes, including labelling and completing the form.

3 Trial a super-potent steroid and emollient to distinguish Bowen’s disease from eczema

Bowen’s disease is sometimes mistaken for eczema. Bowen’s disease presents as a slow-growing, scaly patch that does not go away (see Figure 2, below). It can look like a patch of eczema. Patches in Bowen’s disease often occur in sun-exposed sites in patients with sun-damaged skin. One or two patches are usual and they tend not to itch, unlike the multiple itchy patches common to eczema. If the diagnosis is likely to be eczema try 2 weeks of a super-potent steroid and emollient. If the patch improves dramatically it is probably eczema. If it does not respond, suspect Bowen’s disease, in which case either treat with a topical agent, refer, or take a biopsy. Be alert also for superficial basal cell carcinoma and look for the slightly raised (whipcord) edge to this patch (see Figure 3, below).

Bowen dermoscopy

Figure 2: Bowen dermoscopy

Source: Image from DermNet NZ. Reproduced with permission

Superficial basal cell carcinoma

Figure 3: Superficial basal cell carcinoma

Source: Image from DermNet NZ. Reproduced with permission

4 Avoid soap

Eczema is a skin barrier problem; the skin has lost some of its protective lipid barrier and is, therefore, susceptible to irritation.4 A key element of treating patients with eczema is to provide a protective barrier. Soap of any kind removes grease, denudes the skin’s protective barrier, and should be avoided. Unfortunately, people are conditioned to using soaps and shower gels and are sometimes difficult to convince. An explanation and supply of a suitable soap substitute may help to persuade them, but not always. In patients who do not respond to treatment, recheck that they are avoiding soap.

5 Use emollients correctly and in large quantities

The skin requires protection and a good greasy barrier makes all the difference. Most patients use too little emollient and do not apply it properly. An adult with moderately severe eczema over the whole body might initially need to use 500 g in 7–10 days. Ask patients how much emollient they are using. How long does a big pot last? The answer is usually several months. Ask patients how they apply emollient and to show you if they can. They usually take a small blob and rub it in. Show patients how to use it properly.4 Take a large handful, apply it fairly thickly like a paint, and let it soak in for 10 minutes. Patients immediately say the skin itches less.

Sometimes an emollient stings inflamed skin and patients conclude they are ‘allergic’ to it. Explain that it is not an allergy and advise them to try it for a few days; usually they will find that their condition improves and the emollient no longer stings. If a patient appears sensitive to one emollient, try another or test for 3 days on a forearm to see if there is any reaction. The patient will need to be confident to use the emollient so each person needs to be managed differently.

6 Use topical steroids appropriately

Both doctors and patients can fear that use of topical steroids will thin the skin. Therefore, a steroid that is too weak tends to be prescribed for too short a period and the condition does not resolve. A thin covering of a potent steroid should be used for the appropriate length of time and applied once daily.4 Potent steroids should be avoided in the axillae as they tend to cause atrophy. The fingertip unit (FTU) can be used as a guide to how much steroid should be applied to a given area (see Figure 4, below); one FTU—the amount of cream that is squeezed from a tube along a fingertip—is about 0.5 g.

Fingertip unit

Figure 4: Fingertip unit

FTU=fingertip unit

The steroid should be applied after the emollient has been absorbed into the skin (10–15 minutes), but this is not a rigid recommendation. A gap of at least 10 minutes between applications is key.6

The length of steroid course is difficult to gauge but a guide is to continue this until the area stops itching; usually a few days but can be longer on the hands, feet, and scalp. Another tip is to apply the steroid once a week to areas of recurrence, even when they are quiescent.7

7 Use the right topical steroid for the right site

The techniques used to treat eczema vary, depending on the area affected. A broad generalisation is provided in Table 2 (below).

Table 2: Topical steroid strength and length of treatment for selected skin areas
Site/typeSteroid strengthTreatment length
Face and flexures Moderate Once or twice daily for up to 1 week
Eyelids Weak or moderate Once daily for a few days
Body Potent Once daily for 2 weeks, and 4 weeks maximum
Hands and feet
Lichen simplex
Super potent
Occlusion is sometimes necessary
Once daily for 2 weeks and possibly longer
Scalp Potent or super potent Once daily for 2 weeks. Stop when the condition has settled

Sometimes the problem requires regular applications of steroid and patients develop tachyphylaxis, in which case they are best referred to dermatology. However, repeating tips 4, 5, and 6, and ensuring they are adhered to, solves many issues.

Tacrolimus and pimecrolimus are sometimes helpful as steroid-sparing, topical anti-inflammatory treatments but they are more expensive, can sting when applied, and are often not on GP prescribing formularies. However, this does not mean that GPs should not consider their use on occasion.

8 Remember that persistent eczema is often infected

Many patients with atopic eczema develop Staphylococcus aureus infection. If the eczema is not settling add an oral antibiotic, usually flucloxacillin, for 1–2 weeks.8 Topical fusidic acid is sometimes helpful but resistance develops quickly in patients who use it regularly so it becomes less useful.9

Weekly baths containing half a cupful of plain bleach added to one full tub of water can be used to treat infected eczema, but patients (and/or their parents/carers) are often reluctant to try this treatment.10 Caution should be advised.

Topical antiseptics, such as chlorhexidine, are useful but can dry the skin so it is important to ensure that moisturisers are used appropriately.

Some emollients have antiseptic properties and are thought to be helpful.

9 Use wet wraps in children

The evidence for using wet wraps is not strong but they can be useful for a few days in children to reduce scratching and settle eczema.

Apply a thick covering of emollient to the affected area and wrap the skin in the wet bandages. The skin is cooled by evaporation of water from the bandages. The wet wrapping locks the moisturiser in the skin.

Dry bandages should be applied immediately on top of the wet bandages. If socks or other tubular-shaped fabrics are being used for the wet layers, the dry bandages should be slightly larger than the wet bandages so that they can be applied more easily. Otherwise, wrap the dry bandages firmly, but not too tightly, around the wet bandages. Dry bandages serve as a seal for the moisturiser and wet bandages, and also protect clothes and bedsheets.

Some wet wrap suits are available on FP10 prescription.

10 Do not rush to do food allergy tests in children

A true food allergy reaction occurs within 30 minutes of food ingestion. However, food sensitisation is fairly common in patients with atopic eczema. It leads to raised levels of specific immunoglobulin E (IgE), but does not necessarily represent a food allergy. Testing IgE levels often leads to children being placed on very restrictive diets because they have high levels of food-specific IgE but they are not, in fact, allergic to those foods. The food challenge is the only true test of food allergy.11 Exclusion diets can be useful but need to be introduced after consultation with an immunologist.

Therefore, it is best to test children for food allergies only if they have:

  • persistent eczema despite optimised topical management
  • a reliable history of an immediate reaction to a food.

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References

  1. National Eczema Society. What is eczemawww.eczema.org/what-is-eczema (accessed 16 March 2017).
  2. Simpson C, Newton J, Hippisley-Cox J, Sheikh A. Trends in the epidemiology and prescribing of medication for eczema in England. J R Soc Med 2009; 102 (3): 108–117.
  3. Darsow U, Eyerich K, Ring J. Eczema pathophysiologywww.worldallergy.org/education-and-programs/education/allergic-disease-resource-center/professionals/eczema-pathophysiology (accessed 16 March 2017).
  4. Primary Care Dermatology Society. Eczema—atopic eczemawww.pcds.org.uk/clinical-guidance/atopic-eczema (accessed 16 March 2017).
  5. Primary Care Dermatology Society. Psoriasis: an overview and chronic plaque psoriasiswww.pcds.org.uk/clinical-guidance/psoriasis-an-overview (accessed 16 March 2017).
  6. Penzer R. Best practice in emollient therapy: a statement for healthcare professionals December 2012. Dermatological Nursing 2012; 11 (4): S1–S19.
  7. National Eczema Society. Topical steroids. www.eczema.org/corticosteroids (accessed 16 March 2017).
  8. NICE. Atopic eczema in under 12s: diagnosis and management. NICE Clinical Guideline 57. Available at: www.nice.org.uk/cg57
  9. Medicines and Healthcare Products Regulatory Agency. Public assessment report—fusidic acid 2% cream. London: MHRA, 2014. Available at: www.mhra.gov.uk/home/groups/par/documents/websiteresources/con491146.pdf
  10. American Academy of Dermatology website. Atopic dermatitis: bleach bath therapywww.aad.org/public/diseases/eczema/atopic-dermatitis#bleach-bath (accessed 16 March 2017).
  11. Bergmann M, Caubet J, Boguniewicz M, Eigenmann P. Evaluation of food allergy in patients with atopic dermatitis. J Allergy Clin Immunol: In Practice 2013; 1 (1): 22–28. G