Treatment of Chronic Itch in Atopic Dermatitis With Topical Naltrexone

Itch was recently identified as one of the top three priority topics in dermatology at a Research Agenda Conference sponsored by the American Academy of Dermatology in 2012. Chronic itch is a complex phenomenon, involving the skin, immune and nervous systems to various degrees. Therefore, focusing on a particular pruritic disease will enable us to work out the underlying pathophysiological mechanisms that occur between the skin and the brain to establish a rational treatment approach. Atopic Dermatitis (AD) is defined as a chronic inflammatory dermatological disease characterized by immunological and neurological cutaneous hyperreactivity with ongoing itch and inflammation. It is linked to an atopic predisposition with skin barrier abnormalities, recurrent delayed-type inflammations; frequently the development of IgE-mediated inhalant and gastrointestinal-related immediate type reactions. It is estimated that the prevalence for AD is at least 17% of the population lifetime worldwide with some reports of increasing prevalence in the last decades. It is also increasingly being observed in the aging population with dry, itchy skin. Various topical and systemic therapies are available and choices are based on disease extent, presence of acute flare, and age of the patient. Unfortunately, itch in AD can be challenging to control; although multiple topical and systemic treatments are available, to date no universally accepted treatment exists. The investigators have previously shown that opioid receptors play an important role in pruritus. Therefore, the investigators plan on expanding on previous and ongoing experiences with opioid antagonists and study the epigenetic and molecular mechanisms behind. Moreover, the investigators have recently discovered that the endogenous opioid ligand Met-Enkephalin influences circadian rhythm by binding directly to CLOCK gene promoters in the nucleus, which then change the amplitude and phase-shift these genes in keratinocytes. Ultimately, the investigators would like to evaluate the effectiveness of topical application of Naltrexone in an effort to potentially help to treat chronic, untreatable itch and learn more about peripheral disorders of sensation (itch and pain).