A red spot on the scalp is common, prompting concern. These spots can arise from various factors, from minor irritations to health conditions. While many are harmless and resolve on their own, some require medical attention. Understanding potential causes helps determine when to seek evaluation.
Inflammatory and Irritation-Related Spots
Red spots on the scalp stem from inflammation or irritation. Seborrheic dermatitis, commonly known as dandruff in its milder form, is a prevalent skin condition causing flaky, red patches on the scalp. These patches can appear greasy and may be accompanied by itching.
Psoriasis is an autoimmune disorder that can manifest on the scalp as thick, silvery scales over red patches. This condition results from an accelerated skin cell growth cycle and can cause intense itching, leading to bleeding from scratching.
Contact dermatitis occurs when the scalp reacts to substances it touches, such as certain hair products or dyes. This reaction can lead to redness, itching, swelling, or blisters or oozing.
Sunburn is a direct irritation that can cause red, painful, and tender skin on the scalp, especially in areas with less hair density. Severe cases may involve blistering and subsequent peeling of the skin.
Infectious Causes of Scalp Spots
Red spots on the scalp signal microbial infections. Folliculitis, an inflammation or infection of hair follicles, appears as small, red, pimple-like bumps that might be itchy or tender. These bumps can be filled with pus and may form crusts. Bacterial or fungal organisms can cause folliculitis, leading to localized breakouts.
Ringworm of the scalp, medically termed tinea capitis, is a fungal infection that presents as scaly, itchy, red patches. Hair loss in the affected area is a common symptom, appearing as “black dots” where hairs have broken off at the scalp surface. This fungal infection is contagious and spreads through direct contact or shared items.
Other Common Non-Serious Causes
Beyond inflammation and infection, several common factors can lead to red spots on the scalp without serious implications. Insect bites, from sources like mosquitoes or fleas, can cause localized red, itchy bumps on the scalp. These reactions are transient and resolve as the body processes the irritant.
Ingrown hairs can create small, red, and sometimes painful bumps when a hair curls back into the skin instead of growing outward. This occurs after shaving or other hair removal practices.
Cysts, such as epidermoid or pilar cysts, can appear as firm bumps under the skin. If these cysts become inflamed or infected, they can turn red and become tender.
When to Seek Medical Evaluation
Consult a medical professional if a red spot on the scalp exhibits certain characteristics or is accompanied by other symptoms. Seek evaluation if the spot becomes painful, increasingly uncomfortable, or rapidly grows in size. A doctor should also assess any spot that changes in appearance, bleeds, oozes, or fails to heal within a few weeks.
Additional symptoms such as fever, chills, or a widespread rash alongside the scalp spot warrant prompt medical attention.
If there is significant hair loss associated with the spot, or if the spot causes considerable distress, a professional can accurately identify the cause and recommend suitable management.
Concerning and Potentially Serious Conditions
While many scalp spots are benign, some red spots can indicate more serious conditions, including various forms of skin cancer. Actinic keratoses are rough, scaly patches resulting from prolonged sun exposure, considered pre-cancerous. These lesions can be light or dark, tan, pink, or red, and may feel rough like sandpaper. Untreated actinic keratoses have a risk of progressing to squamous cell carcinoma.
Basal cell carcinoma (BCC), the most common type of skin cancer, can appear on the scalp as a pearly or waxy bump, a flat, flesh-colored lesion, or a scar-like brown spot. Squamous cell carcinoma (SCC), the second most common type, presents as a firm, red nodule or a flat lesion with a scaly, crusted surface that may bleed easily. Both BCC and SCC are linked to sun exposure.
Melanoma, the most serious type of skin cancer, can also occur on the scalp. It might appear as a new spot or a changing mole, with irregular shapes, varied colors (blue, black, tan, brown, red), and uneven borders. Early detection of any suspicious spot is important for these conditions, and a medical professional can provide a definitive diagnosis through examination and biopsy.