Recent research reveals that scratching an itch may actually enhance the body’s defenses against bacteria, challenging conventional wisdom. While scratching can provide immediate relief, it also poses risks by worsening conditions like eczema and reopening wounds.
A study conducted by researchers at a leading university utilized allergens known as haptens to stimulate eczema-like symptoms in mice. The findings showed that mice allowed to scratch their ears exhibited greater swelling and higher levels of neutrophils—critical cells in the immune response—compared to those restricted from scratching.
Investigating the cellular responses, researchers discovered that scratching activates pain-sensing neurons that release a chemical called substance P. This process subsequently stimulates mast cells, leading to an increase in neutrophil production, which plays a vital role in fighting infections, according to research findings.
The study also indicated that scratching significantly reduced the presence of Staphylococcus aureus, a bacterium often responsible for skin infections and dermatitis. The researchers noted that just 24 hours of scratching could lead to measurable changes in the skin’s microbiome.
Despite these advantages, the team cautioned that the same allergens responsible for itching can trigger inflammatory pathways, potentially exacerbating conditions like eczema. “While moderate scratching can be beneficial, excessive scratching may lead to increased skin damage,” explained a lead researcher.
Preliminary evidence suggests that the positive effects of scratching may extend to humans, hinting at a complex relationship between itch, immune response, and skin health.
