Curcuminoids, the active polyphenolic compounds in turmeric (Curcuma longa), have been investigated for their anti-inflammatory and antioxidant properties, which are relevant to the pathophysiology of dermatitis, particularly atopic dermatitis and contact dermatitis. Several preclinical studies have demonstrated that curcumin (the primary curcuminoid) can inhibit the expression of pro-inflammatory cytokines such as TNF-α, IL-1β, and IL-6, and modulate NF-κB signaling pathways in skin cells. This suggests a plausible biological rationale for curcuminoids' potential benefit in inflammatory skin conditions.

Human evidence is limited but growing. Small randomized controlled trials (RCTs) and pilot studies have evaluated topical curcumin formulations and oral supplementation in patients with various forms of dermatitis. For example, a 2015 pilot study found significant improvement in symptoms and severity scores in patients with atopic dermatitis using a turmeric-based cream compared to placebo. Another RCT published in 2019 reported that oral curcumin supplementation provided mild symptomatic relief in atopic dermatitis, though results were modest and methodological concerns (such as small sample sizes and lack of blinding) limit the strength of conclusions.

In summary, there is moderate preclinical evidence and preliminary clinical support for curcuminoids as a supplementary intervention in dermatitis, primarily due to their anti-inflammatory effects. However, large, high-quality clinical trials are needed to confirm efficacy and safety.