Alopecia and Associated Toxic Agents: A Systematic Review

Area of Science:

• Toxicology
• Dermatology
• Pharmacology

Background:

• Alopecia can be a clinical sign of toxic agent overdose.
• Identifying these agents is crucial for diagnosis and treatment.

Purpose of the Study:

• To review and summarize known toxic agents that cause alopecia.
• To assess the strength of evidence linking various substances to hair loss.

Main Methods:

• Systematic literature search of PubMed, EMBASE, and Cochrane databases.
• Inclusion of 47 studies from an initial 856 articles reviewed.
• Focus on studies describing hair loss due to toxic agent exposure or ingestion.

Main Results:

• Strong evidence links thallium, mercury, selenium, and colchicine to alopecia.
• Other implicated agents include boric acid, arsenic, vitamin A, botulinum toxin, Podostroma cornu-damae, and MT-45.
• Evidence strength varies significantly among identified agents.

Conclusions:

• Multiple toxic agents are associated with alopecia, with differing levels of scientific support.
• Established agents like thallium and colchicine contrast with less-studied ones like botulinum toxin A and synthetic opioids.
• Understanding these associations aids in diagnosing patients presenting with hair loss.