Topical Botanical Agents for the Treatment of Psoriasis: A Systematic Review

Background: Patients with psoriasis often enquire about the use of numerous botanical therapeutics. It is important for dermatologists to be aware of the current evidence regarding these agents. Methods: We conducted a systematic literature search using the PubMed, MEDLINE, and EMBASE databases for controlled and uncontrolled clinical trials that assessed the use of topical botanical therapeutics for psoriasis. The search included the following keywords: ‘psoriasis’ and ‘plant’ or ‘herbal’ or ‘botanical’. We also reviewed citations within articles to identify additional relevant sources. We then further refined the results by route of administration and the topical botanical agents are reviewed herein. Results: A total of 27 controlled and uncontrolled clinical trials addressing the use of topical botanical agents for psoriasis were assessed in this review. We found that the most highly studied and most efficacious topical botanical therapeutics were Mahonia aquifolium, indigo naturalis, aloe vera, and, to a lesser degree, capsaicin. The most commonly reported adverse effects were local skin irritation, erythema, pruritus, burning, and pain. However, the overall evidence for these therapeutics remains limited in quantity and quality. Conclusion: The literature addresses a large number of studies in regard to botanicals for the treatment of psoriasis. While most agents appear to be safe, further research is necessary before topical botanical agents can be consistently recommended to patients.