What tests will I/my child need for a diagnosis of eczema?

What tests will I/my child need for a diagnosis of eczema?

When you visit your doctor to talk about your skin problems, they should ask you some detailed questions so that they can determine the likelihood of eczema and exclude other potential diseases. They will also carefully and thoroughly examine your skin.

Your personal and family history

Questions that your doctor should ask include:

  • Your current health and any medications you are taking - prescribed or over-the counter
  • Your past medical history, including any skin diseases, allergies (including food allergies), or skin infections
  • The personal hygiene, laundry and cleaning products that you use around the house
  • When the skin problems first started, their pattern on the body, and when they become worse 
  • Any treatments you have previously tried for your skin problems and whether they were effective
  • History of parental allergy, asthma or eczema - this significantly increases the risk of a child developing eczema1,2
  • Your occupation and whether your work with certain substances known to be irritant to skin in sensitised people, e.g. latex gloves, hair dye, nickel3-5

You should always tell your doctor how eczema affects you/your child and your family, including:

  • Symptoms interrupting sleep
  • Itching, especially in embarrassing places
  • Social embarrassment due to visible skin lesions - do you have to miss out on activities such as swimming or playing with pets?
  • Difficulties at work - do you have to wear certain clothes or gloves?
  • Do you worry about your child's future due to their eczema?

Skin examination

Your whole body should be examined in natural light: the doctor should look at any skin lesions and inflammation, and record any physical effects, such as itch and pain that you have been experiencing. Every area of skin must be examined, including the scalp. 

Following these questions and the skin examination, your doctor may make a diagnosis of eczema if an itchy skin condition is present (or your child is frequently scratching or rubbing their skin), plus at least three of the following:6

  1. History of involvement of the skin creases such as folds of the elbows, behind the knees, fronts of ankles or around the neck (including cheeks in children aged under 10 years)
  2. A personal history of asthma or hay fever (or history of atopic disease in a first-degree relative in children aged under 4 years)
  3. A history of generalised dry skin in the last year
  4. Visible eczema in the body creases (or eczema involving the cheeks or forehead and outer limbs in children aged under 4 years)
  5. Onset of signs and symptoms age under 2 years

Note that skin tests for allergies are not routinely recommended for making a diagnosis of atopic eczema.9

Is eczema linked to food allergies?

The relationship between eczema and food allergy is complex. In children aged under 2 years and with a clinician or dietician-diagnosed food hypersensitivity (e.g. cow's milk, hen's egg, peanut, etc.) the incidence of eczema is higher than in children without food allergy. Eczema is the first symptom in around 40% of children with food hypersensitivity.5 Conversely, infants with eczema show an increased risk of food allergy. These allergies may include peanut, egg white, sesame and cow's milk.8

References

  1. Apfelbacher CJ, Diepgin TL, Schmitt J. Determinants of eczema: population-based cross-sectional study in Germany. Allergy 2011;66:206--13.
  2. Taylor-Robinson DC, Williams H, Pearce A et al. Do early-life exposures explain why more advantaged children get eczema? Findings from the UK Millennnium Cohort Study. Br J Dermatol 2016;174:569--78.
  3. Kranke B, Schuster C. Contact dermatitis: relevant differential diagnoses, simulators, and variants. J Dtsch Dermatol Ges 2015;13:1073--88.
  4. oshihisa Y, Shimizu T. Metal allergy and contact dermatitis: an overview. Dermatol Res Pract 2012;2012:Article ID 749561.
  5. Hansen HS, Johansen JD, Thyssen JP et al. Personal use of hair dyes and temporary black tattoos in Copenhagen hairdressers. Ann Occup Hyg 2010;54:453--458.
  6. Williams HC, Burney PGJ, Pembroke AC et al. The UK Working Party's diagnostic criteria for atopic dermatitis. III. Independent hospital validation. Br J Dermatol 1994;131:406--16.
  7. Grimshaw KEC, Bryant T, Oliver EM et al. Incidence and risk factors for food hypersensitivity in UK infants: results from a birth cohort study. Clin Transl Allergy 2016;6:1.
  8. Martin PE, Eckert JK, Koplin JJ et al. Which infants with eczema are at risk of food allergy? Results from a population-based cohort. Clin Exp Allergy 2015;45:255--64.
  9. Scottish Intercollegiate Guidelines Network. Management of atopic eczema in primary care. March 2011. Available at: (http://www.sign.ac.uk/pdf/sign125.pdf). Last accessed: August 2016.

UK/GEN/16/0051 Date of preparation: October 2016