A mole (nevus) is a common skin growth formed when pigment-producing cells (melanocytes) grow in clusters. Changes in a mole’s appearance or sensation, such as itching (pruritus), often cause concern due to the association with skin cancer. This article examines the relationship between pruritus and malignant melanoma.
How Itching Relates to Melanoma Risk
The presence of itching alone does not confirm melanoma, but it is a recognized potential symptom of this skin cancer. Pruritus occurs in approximately 22% of primary malignant melanoma lesions. This sensation may result from the body’s inflammatory or immune response to rapidly growing cancerous cells. The uncontrolled expansion of the tumor can also physically irritate delicate nerve endings in the skin layers.
The development of new symptoms like itching or tenderness indicates evolution, which warrants medical evaluation. However, itching often serves as an additional sign accompanying visual changes, rather than the first symptom noticed.
Benign Reasons Moles Become Irritated
Most itchy moles are unrelated to skin cancer and result from simple, non-malignant irritation. A common cause is mechanical friction, where a mole is constantly rubbed by clothing seams, bra straps, or belts. This persistent rubbing irritates the skin around the nevus, causing inflammation and an urge to scratch.
Dry skin (xerosis) or conditions like eczema or dermatitis can also cause generalized itching that affects a pre-existing mole. Minor injuries, such as scratches or insect bites, can directly irritate a mole. Environmental factors like sunburn can inflame the surrounding skin, causing temporary itching and tenderness. These non-cancerous causes are usually temporary and resolve once the source of irritation is removed or the underlying condition is treated.
The Key Visual Signs of a Suspicious Mole
Visual changes in a mole are a more reliable indicator of potential malignancy than itching alone. Dermatologists use the ABCDE method to help patients self-examine their skin for signs of melanoma. This method focuses on five distinct characteristics that differentiate a benign mole from a potentially malignant one.
The letter ‘A’ stands for Asymmetry. If you draw a line through the middle of the mole, the two halves do not match. Benign moles are typically symmetrical, so a lopsided or uneven appearance warrants closer inspection.
‘B’ represents Border irregularity. This means the edges of the mole are ragged, notched, blurred, or poorly defined. A healthy mole usually has smooth, distinct borders, and indistinct margins are a warning sign.
‘C’ refers to Color variation. A suspicious lesion may display varying shades of brown, black, white, red, or blue within the same spot. A typical mole is usually a single, consistent shade of brown, tan, or black.
‘D’ is for Diameter. Moles larger than 6 millimeters, roughly the size of a standard pencil eraser, should be viewed with caution. While melanomas can be smaller, a large size increases the need for professional evaluation.
The final letter, ‘E’, stands for Evolving. Any change over time in the mole’s size, shape, color, or elevation is concerning. This also includes new symptoms such as itching, tenderness, bleeding, or crusting, making evolution the most critical factor.
Guidelines for Seeking Medical Evaluation
If a mole exhibits any of the ABCDE signs or develops persistent, new symptoms, it should be examined by a dermatologist. You should schedule an appointment for any mole that is new or has been rapidly changing in appearance over a short period.
A professional evaluation is also recommended if a mole itches persistently, or begins to bleed or hurt, even if the visual appearance seems benign. Early detection is a major factor in the successful treatment of melanoma, making prompt consultation prudent.