Advances in the use of topical imiquimod to treat dermatologic disorders

Abstract

Imiquimod (IQ) is an immune-response modifying agent, fi rst approved by FDA for the topical treatment of external genital and perianal warts in 1997. It induces, through stimulation of Toll-like receptors (TLRs) localized on the surface of antigen-presenting cells, synthesis and release of several endogenous pro-infl ammatory cytokines such as interferon-α (IFN-α), tumor necrosis factor-α (TNF-α) and interleukins (IL) 6 and 12, which in turn stimulate both the innate and acquired immune pathways, resulting in upregulation of natural antiviral and antitumor activity. IQ 5% cream has been used for the treatment of a wide variety of dermatologic conditions in which the immune system is thought to play a role in regression of the disease. In some disorders, such as genital and perianal warts, actinic keratoses, basal cell carcinomas, Bowen's disease and molluscum contagiosum, relative safety and effi cacy are supported by randomized controlled trials of IQ. However, it is common for patients to experience local skin reactions, which can range from mild to severe in intensity, but usually resolve 1-2 weeks after interrupting treatment. Additional randomized trials are encouraged to assess safety and effi cacy of IQ in the treatment of an even wider range of cutaneous disorders.

Induction of vitiligo after imiquimod treatment of condylomata acuminata

“…Moreover, imiquimod can induce cytokines such as IFN-α, TNF-α, IL-6, IL-8, and nitric oxide to cause vitiligo [ 16 ]. Additionally, imiquimod binds to Toll-like receptor-7 and −8, increasing production of proinflammatory cytokines such as IFN-α, TNF-α, and LI-12 [ 17 , 18 ], which play a role in the pathogenesis of vitiligo.…”

Treatment Outcomes of Adjunct and Stand-alone Photodynamic Therapy in Patients With Extramammary Paget Disease: A Literature Review

“…As the treatment is applied topically, local reactions are common, and the drug has a low chance of reaching systemic circulation. 49,51…”

“…As the treatment is applied topically, local reactions are common, and the drug has a low chance of reaching systemic circulation. 49,51 This study has a few limitations, including the small sample sizes of the studies that were included in the analysis. In addition, inconsistencies between the PDT machines and settings used make it difficult to conduct direct comparisons.…”

Imiquimod induced vitiligo‐like lesions—A consequence of modified melanocyte function

“…1 , 2 The antiviral, antitumor, and immunomodulatory properties of imiquimod are valuable to treat benign and malignant skin diseases as genital warts, actinic keratosis, and superficial basal cell carcinoma. 3 , 4 In line with more frequent clinical applications in dermatology 5 , 6 reports of hypopigmented lesions related to the use of imiquimod increased. 7 , 8 , 9 , 10 , 11 , 12 , 13 A cytotoxic T‐cell‐mediated immune response has been suggested causing the imiquimod‐induced depigmentation, 14 however, the exact mechanisms are still unclear.…”