A skin mole, medically known as a nevus, is a common growth resulting from a cluster of melanocytes, the cells responsible for producing pigment. These growths typically appear as small, dark spots that are benign and pose no health risk. While most moles are harmless, they can itch for many benign reasons. However, persistent or new itching can sometimes be a symptom that warrants medical attention.
Common Reasons Moles Become Irritated
Moles are composed of skin tissue, making them susceptible to the same irritations that affect the surrounding skin. A common cause of temporary itchiness is physical friction from everyday objects rubbing against a raised mole. This often occurs in areas where clothing is tight, such as along a waistband, under a bra strap, or where jewelry rests against the skin.
Environmental factors can also trigger irritation and itching in a mole. Dry skin or conditions like eczema affecting the skin around a nevus can cause a generalized sensation of itchiness that includes the mole itself. An allergic reaction to topical products, such as a new body wash or laundry detergent, can also lead to localized inflammation.
Minor trauma, like a bug bite or a scratch that breaks the skin’s surface, will naturally cause temporary itching and inflammation. These temporary causes are usually self-limiting, meaning the itchiness subsides once the irritant is removed or the injury heals. If the itching resolves quickly and there are no other changes to the mole, the cause is likely not related to a deeper cellular problem.
Itching as a Potential Sign of Atypical Change
While most itchy moles are benign, persistent or new itching can be a warning sign associated with melanoma, the most serious form of skin cancer. Melanoma develops when the melanocytes within a mole begin to grow and divide uncontrollably. Itchiness, or pruritus, is thought to occur because the rapidly growing cancerous cells release substances that irritate nerve endings in the skin.
Dermatologists use the ABCDE mnemonic, a well-established screening tool, to help identify moles showing signs of atypical change. The “A” stands for Asymmetry, meaning one half of the mole does not match the other half in shape. The “B” refers to Border irregularity, where the edges are ragged, blurred, or notched rather than smooth.
The “C” represents Color variation, indicating multiple shades of tan, brown, black, or sometimes red, white, or blue within the same mole. The “D” is for Diameter, as melanomas are often larger than 6 millimeters, roughly the size of a pencil eraser.
The final sign is the “E,” which stands for Evolving. This includes new or changing symptoms like persistent itching, tenderness, or bleeding. When itching is persistent, worsens over time, or is accompanied by changes in the mole’s size, shape, or texture, it indicates a potential internal cellular change. The combination of persistent itching with any of the other ABCDE features requires professional evaluation.
Monitoring Moles and Consulting a Specialist
Regular self-examination is the best tool for early detection, as you are the person most familiar with your own skin. It is recommended to perform a full-body check monthly, paying close attention to any spot that looks different from the others, often called the “ugly duckling” sign. Use mirrors to check hard-to-see areas like the scalp, back, and soles of the feet.
You should schedule an appointment with a dermatologist if a mole begins to itch and the sensation does not resolve within two weeks, or if it is accompanied by other worrying changes. Other symptoms requiring immediate attention include a mole that bleeds without being scratched, develops a crust, or shows any signs of the ABCDE criteria.
During a consultation, a specialist will examine the mole using a dermatoscope, a magnifying tool that provides a closer look at the pigment structure. If the mole appears suspicious, the dermatologist may recommend a biopsy, which involves removing all or part of the mole for microscopic analysis. This is the only way to definitively determine if the mole is benign or malignant, allowing for effective treatment if cancer is detected.