What Are Bumps & Itching on the Scalp Caused From?

Itchy bumps on the scalp can occur for many reasons. Although most conditions aren't harmful, their symptoms can be embarrassing and uncomfortable. Understanding what causes scalp irritation can help you diagnose and remedy its effects.

Seborrheic Dermatitis

According to the Mayo Clinic, seborrheic dermatitis can cause itchy, scaly bumps on the scalp 2. In infants, this condition is referred to as cradle cap. Although the cause:

  • for seborrheic dermatitis is unknown
  • several factors contribute: the malassezia fungus that can grow in the sebum excreted from the skin
  • season changes
  • fatigue
  • neurological disorders,
  • HIV or AIDS 2

Medicated shampoos can treat seborrheic dermatitis 2. Look for one containing ciclopirox, tar, salicylic acid, ketoconazole or pyrithione zinc. If the condition persists, consult a dermatologist or doctor. He can prescribe a prescription-strength shampoo or steroid lotion.


The U.S. National Library of Medicine says hives can result in itchy, red welts 1. This allergic reaction can occur anywhere on the body, including the scalp. When the body encounters an allergic substance, it floods the bloodstream with histamine. Common triggers include bug bites, pollen, pet dander and shellfish. As a result, hives can erupt. If mild, hives may not require treatment. However, to reduce swelling and itching, avoid hot showers and tight clothing. Consider taking an antihistamine such as diphenhydramine to reduce symptoms. Severe hives require medical attention. You may need an emergency injection of steroids or adrenaline.

Seborrheic Keratoses

Seborrheic keratoses causes the development of small, benign bumps on the skin and scalp 3. Although this medical condition tends to run in families, the American Academy of Dermatology says its cause is not known 3. Treatment is not typically necessary. However, if the lesion turn black, itches, bleeds or grows quickly, consult a dermatologist. The growth must be biopsied to ensure it's not cancerous. To remove it, a doctor may perform cryosurgery, in which liquid nitrogen is used to freeze off the growth. Or he may cauterize the lesion with electrosurgery.