Opioids and the skin--where do we stand?

Area of Science:

• Dermatology
• Neuroscience
• Immunology

Background:

• The skin and nervous systems share an ectodermal origin, suggesting inherent interactions.
• The opioid system, involving opioid receptors (OR) and endogenous agonists, is increasingly recognized in skin structures.
• These interactions provide bidirectional control between the central nervous system and peripheral skin/immune systems.

Purpose of the Study:

• To review the current understanding of the peripheral opioid system's role in skin physiology and pathology.
• To highlight the therapeutic potential of targeting skin-associated opioid interactions for pain and pruritus management.
• To explore the impact of cutaneous opioid system activation on skin repair processes.

Main Methods:

• Literature review of studies investigating opioid system components in skin.
• Analysis of evidence for functional opioid receptors and agonists in various skin cell types.
• Examination of the influence of peripheral opioid signaling on skin cell behavior and immune responses.

Main Results:

• Opioid receptors and agonists are present and functional in skin nerve fibers, keratinocytes, melanocytes, hair follicles, and immune cells.
• Cutaneous opioid system activation influences cell differentiation and apoptosis, suggesting a role in skin repair.
• Topical opioid ligand application shows promise for localized treatment of pain and pruritus with reduced systemic side effects.

Conclusions:

• The peripheral opioid system is a significant modulator of skin function and pathology.
• Targeting skin-based opioid interactions presents a promising strategy for treating chronic and acute skin conditions.
• Further research is needed to fully elucidate the complex roles of the peripheral opioid system in skin homeostasis and disease.