Features of Atopic Dermatitis (AD) in the Chinese Population (China)

As anywhere in the world, the main problem with both Atopic Dermatitis (AD) and Eczema is…

…ITCH !

-This is the first thing you often see when seeing the patient. He/she scratches until the skin is broken.
-It is obvious to diagnose the condition, when history is obvious but it becomes more difficult when lesions are bilaterally located on the face, hands…

-Sometimes, for a similar lesions the diagnosis of Eczema  versus Atopic Dermatitis (AD) is not obvious and it often depends on the “cultural” sensitivity:

• In Europe, North America,  Japan and Korea, AD is  preferred to eczema
• In China it’s eczema (or endogenous eczema (not otherwise specified))

The cultural view of the term “eczema” is that in China eczema is considered as a disease per se whereas in Europe, North America,  Japan and Korea, its only a descriptive term.

-Dr Zhang JZ and his colleagues (Beijing, China) performed a prospective multi-centre study:

• 42 geographical sites
• over 12 years old
• with a labeled diagnosis of symmetrical eczema or AD
• duration of the disease more than 2 months
• more than 2500 patients were enrolled (check abstract to view how many patoents  !)
• Results:
  • in 84% of cases, the patients lived in urban areas
  • eczema (symmetrical) was diagnosed in 2/3 of cases
    AD was diagnosed one third of the time
  • 77% of patients developed the condition after the age of 12 (late onset) AD
  • Blood tests showed the following:
    • IgE elevated in half patients
    • eosinophilia in a third of cases
    • increase of both in 60% of patients

Zhang proposed revised criteria for AD (a simplified and adapted form of Hanifin and Rajka criteria):

• necessary feature: symmetrical eczema of 6 months duration or more.
• in addition one of the following:
  family history of AD
  IgE or eosinophils or allergen elevated
• exclusion of other causes such as drug eruptions, malignancy and Hyper IgE syndrome.

According to this study:

• half of patients having AD have a mild form
  4/10 of patients have a moderate form
  in 10% of cases, it is severe
• Features of AD in adults:
  • xerosis (74% of adults with AD)
  • nipple eczema (7.9%)
  • white dermographism (20%)
  • Dennie-Morgan sign (6%)
  • nummular eczema (20%)
  • Perineum eczema (15%)
  • periauricular eczema/fissuring (25%)

Comments

-It remains to be seen if non-cutaneous criteria of AD (Asthma , Allergic Rhinitis) could be systematically included in a prospective study.
-A study outside of China could be interesting (multicentre International stdy involving Han Chinese)

Zhang JZ. Many faces of adult atopic dermatitis. Global Chinese Dermatology Summit (GCDS) Symposium. World Congress of Dermatology 2015 –  Vancouver, Canada