Methamphetamine is a powerful, highly addictive stimulant causing severe physical and psychological consequences. Among the most visible effects of chronic use are persistent skin lesions, commonly called “meth sores” or “meth mites.” These open wounds, primarily on the face and extremities, result from a convergence of the drug’s physiological effects, drug-induced psychosis, and impaired healing. Understanding these factors explains why these lesions appear and persist.
How Methamphetamine Compromises Skin Health
Methamphetamine use directly alters the body’s physical state, creating a weakened and vulnerable environment for the skin. The drug acts as a potent vasoconstrictor, causing a severe narrowing of blood vessels, particularly in the skin’s surface. This prolonged vasoconstriction significantly reduces the flow of blood, oxygen, and nutrients to the skin tissue, leaving the skin stressed and less resilient.
The restricted blood supply accelerates skin aging, giving it a gray appearance and making it brittle and prone to cracking. Severe dehydration frequently accompanies meth use, as the stimulant effect suppresses appetite and thirst. This systemic dehydration further dries out the skin, reducing its elasticity and protective barrier function, making the skin fragile and easily damaged.
The Role of Delusion and Compulsive Picking
The open wounds characterizing meth sores are created by a neurobiological phenomenon known as formication. This tactile hallucination causes the user to experience the terrifying sensation of insects or parasites crawling on or under their skin, often described as “meth mites.” This intense, paranoid delusion is a common feature of methamphetamine-induced psychosis, especially during periods of prolonged wakefulness.
To remove these perceived parasites, users engage in compulsive scratching and digging at their skin, a behavior known as excoriation. This repetitive picking, often focused on the face and arms, directly inflicts the deep, self-made injuries that become open sores. Drug-induced wakefulness and psychosis exacerbate this behavior, leading to continuous re-injury of the same areas.
Impaired Healing and Risk of Secondary Infection
Once open wounds are created by compulsive picking, the drug’s systemic effects prevent effective healing. Chronic methamphetamine use compromises the immune system, slowing the natural repair processes needed to close the sores. The drug impairs the function of immune cells, such as neutrophils, which are responsible for clearing bacteria and cellular debris from wounds.
Methamphetamine also increases matrix metalloproteinase-2 (MMP-2), a protein that contributes to collagen degradation and breaks down the scaffolding needed for tissue repair. This is combined with severe malnutrition, as users often neglect their diet and lack necessary nutrients for tissue regeneration. Poor personal hygiene, common during chronic use, introduces a high bacterial load to the wounds.
This allows common bacteria like Staphylococcus aureus (Staph) to easily colonize and turn simple scratches into persistent, chronic infections. The combination of a weakened immune response, hindered tissue repair, and bacterial contamination causes the lesions to linger, often resulting in scarring.