When atopic dermatitis does not improve despite appropriate treatment, the next step may not always be another medicine. Sometimes the diagnosis itself needs to be reconsidered.
The American Academy of Dermatology has published its first evidence-based guidance specifically addressing diagnostic testing in adults with presumed atopic dermatitis that remains refractory to optimised treatment. The guideline became available online in the »Journal of the American Academy of Dermatology« on 31 August 2026.
Most atopic dermatitis can be diagnosed clinically through medical history and examination. There is currently no single blood test or laboratory biomarker that definitively diagnoses atopic dermatitis. But when appropriately selected treatment repeatedly fails, clinicians need to consider whether another condition could be mimicking atopic dermatitis or existing alongside it.
The new AAD guidance supports diagnostic reassessment in these cases. It discusses situations where additional investigations such as »patch testing, skin biopsy or skin scraping« may be appropriate.
Patch testing can help identify allergic contact dermatitis, which can resemble or worsen atopic dermatitis.
A skin scraping may help investigate infections or other conditions with similar appearances.
A biopsy may be useful when clinicians need to rule out diseases that can mimic chronic atopic dermatitis.
This does not mean every person whose atopic dermatitis remains active needs extensive testing. The guidance specifically concerns adults with presumed atopic dermatitis who are not responding to optimised management. That distinction is important because unnecessary testing can increase costs and anxiety without improving care.
The guideline was developed by a multidisciplinary expert workgroup using the GRADE approach, which systematically considers available evidence and the balance between potential benefits and harms. The authors also acknowledge an important limitation: direct empirical evidence about the best diagnostic work-up for treatment-resistant atopic dermatitis is limited. As a result, part of the guidance relies on indirect evidence and expert consensus.
Still, the guidance addresses a practical problem patients know well. When treatment after treatment fails, the assumption is often that the atopic dermatitis is simply “very severe.”
Sometimes that may be true.
But persistent disease can also reflect another diagnosis, an additional contact allergy, infection or another process complicating the picture. For patients, diagnostic reassessment can therefore be an important form of progress. Before escalating to another systemic medicine, clinicians may sometimes need to return to the beginning and ask one surprisingly valuable question:
Are we certain this is only atopic dermatitis?