Clinical assessment of patients with contact dermatitis

Clinical assessment of patients with contact dermatitis

It is important to distinguish between atopic/endogenous dermatitis from dermatitis which is contact irritant or contact allergic in aetiology.

• a recent study has reported that pattern and morphology of the lesions is often unreliable in differentiating whether the cause is allergic, irritant, or endogenous. This is also true for children with atopic dermatitis

Hence a detailed history is crucial in making the diagnosis, and the causative substance must be determined to resolve the dermatitis and prevent further damage. Patient history should include the following points:

• a personal history of atopic dermatitis in infancy or childhood, presence of other atopic features, such as asthma and hay fever, family history of atopy
  
  
• where did the initial symptoms begin, and where did they spread to later
  
  
• symptoms related to the application or use of any particular product
  • especially hair dyes, cosmetics, personal-care products
  • oral or topical medication
  • clothing, jewellery
  • bandages or personal protection such as gloves
    
    
• a detailed history of all wash products which come into contact with the skin
  • majority of these products contain harsh emulsifiers/surfactants that can cause significant damage to the skin barrier in predisposed individuals such as those with atopic/endogenous dermatitis after a short period of exposure
  • should include every wash product, including shampoos
    
    
• symptoms related to any particular activity, e.g. - hairdressing, holidays, home improvements, painting, decorating, recreation or sport
  
  
• symptoms related to work or specific activity within the workplace
  • a detailed history should be taken, including investigation of practice and products handled at work, supplemented by examination of health and safety data sheets
  • also, personal protection practice such as the use of gloves or goggles should be determined
    
    
• improvement of symptoms when environment changes e.g. - at weekends and during holidays, and recur on return to work
  
  
• symptoms get worse after sunlight exposure
  
  
• any contact with primary skin irritants
  • should include both wet agents (including water and the frequency of hand washing) and which products have been used, as well as dry, desiccating products

Clinical assessment tools should be used for both the initial assessment and the response to treatment of patients with contact dermatitis.

• both generic tools such as the Dermatology Life Quality Index and more specific, objective scoring systems such as the Hand Eczema Severity Index should be considered (1)

Patch testing is the gold-standard investigation in a patient in whom allergic contact dermatitis is considered

• patients who are suspected of having contact dermatitis should be referred to a dermatologist to consider patch testing
• irritant contact dermatitis is a diagnosis of exclusion (when patch tests for allergic contact dermatitis are negative) (1,2)

References:

1. Johnston GA et al. British Association of Dermatologists' guidelines for the management of contact dermatitis 2017. Br J Dermatol. 2017;176(2):317-329
2. Rashid RS, Shim TN. Contact dermatitis. BMJ. 2016;353:i3299.