An overview of drug discovery efforts for eczema: why is this itch so difficult to scratch?

ABSTRACT

Introduction: Atopic dermatitis (AD) is a type of allergic/inflammatory dermatitis characterized by itch and an impairment in quality of life.

Areas covered: Herein, the authors review drug discovery efforts for AD, highlighting the clinical efficacy of novel drugs, with a particular focus on the relief of pruritus. Topical agents include emollients, topical antihistamines, corticosteroids, calcineurin inhibitors and herbs. Recently, topical phosphodiesterase E4 (PDE4) inhibitors like crisaborole have become available and are efficacious for mild to moderate AD with few side effects. For more severe AD, monoclonal antibodies like dupilumab are considered as efficacious subcutaneous treatment options. In severe and recalcitrant AD, systemic treatment can ameliorate AD symptoms.

Expert opinion: Many topical and systemic medications have demonstrated therapeutic benefits for AD. Indeed, randomized trials have shown that topical PDE4 inhibitors and subcutaneous dupilumab are safe and efficacious. Objective tools to evaluate itch and gauge treatment efficacy is important, but current methodology relies primarily on clinical scores. AD is a systemic atopic disease with a lot of complicated psychosocial issues. Suboptimal efficacy is often due to poor compliance and unrealistic expectation of curative treatment, rendering treatment difficult despite the existence of effective medications.

KEYWORDS:

• Atopic dermatitis
• itch
• scratch
• herbal medicine
• fallacies
• phobia

Article highlights

• Topical corticosteroids and calcineurin inhibitors are the mainstay of treatment.

• There are new topical and systemic medications for AD.

• For milder forms of AD, PDE4 inhibitors are effective and safe topical treatment options.

• For more severe AD, subcutaneous dupilumab is an effective agent with a good safety profile and limited adverse effects.

• Well-designed control clinical trials for the use of herbal medicine in the treatment of AD are needed.

• Drug discovery efforts with AD include objective documentation of clinical efficacy to improve disease severity, quality of life and itch in this itchy disease.

• AD is a complex disease with significant psycho-behavioral elements. Non-adherence, phobias (such as steroid phobia), anxiety, stress and unrealistic expectations are among some of most difficult to handle issues despite availability of efficacious topical and systemic medications.

This box summarizes key points contained in the article.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

One referee has served as an investigator for Sanofi, Galderma and Pfizer Inc, while they have also served as a board member and speaker too for Sanofi. Another referee declares acting as a consultant and as a speaker for (and received personal fees from) Sanofi, Pfizer Inc and AbbVie, all who make drugs for atopic dermatitis. Peer reviewers on this manuscript have no other relevant financial relationships or otherwise to disclose.

Additional information

Funding

This manuscript was not funded.