What investigations are recommended for a patient with dermatitis that is not responding to first-line treatments?

For a patient with dermatitis that is not responding to first-line treatments, the following investigations and referrals are recommended:

• Patch Testing: Patch testing should be offered to people with chronic or persistent dermatitis, particularly hand and facial dermatitis, as clinical features alone are unreliable in distinguishing allergic, irritant, and endogenous dermatitis ¹. It is also recommended for previously well-controlled atopic/endogenous dermatitis that has become difficult or impossible to control with the same topical treatments ¹. Identifying the specific allergen through patch testing can increase adherence and improve outcomes ¹.
• Referral to Dermatology:
  • Referral to dermatology is recommended if contact dermatitis may be due to topical treatments such as neomycin or corticosteroids ¹.
  • Consider referral to dermatology if dermatitis, especially hand and facial dermatitis, is severe, chronic, recurrent, or persistent ¹.
  • Refer if previously stable dermatitis has become difficult or impossible to control with standard treatments ¹.
  • Refer if allergy to prescribed or over-the-counter topical treatments is suspected ¹.
  • Refer if suspected contact dermatitis does not respond to treatment in primary care, has atypical features, or the diagnosis is unclear ¹.
  • For atopic eczema, refer for a routine dermatology appointment if current management has not controlled the eczema satisfactorily (e.g., one to two flares per month), or if the person is reacting adversely to many emollients ².
  • Refer if facial eczema has not responded to appropriate treatment ².
  • Refer urgently (within 2 weeks) to dermatology if eczema is severe and has not responded to optimum topical treatment after 1 week ²,³.
  • Refer if contact allergic dermatitis is suspected, for example, if there is persistent eczema or facial, eyelid, or hand eczema ²,³.
  • Refer if the diagnosis is, or has become, uncertain ²,³.
  • Refer if there is recurrent secondary infection ².
  • Refer if eczema is assessed as causing significant social or psychological problems, such as sleep disturbance ²,³.
• Referral for Suspected Food Allergy: Refer to immunology, dermatology, or paediatrics if a food allergy is suspected and the expertise to diagnose and manage food allergy is not available in primary care ²,³.