Medically Reviewed by Jabeen Begum, MD on March 24, 2025
Infectious Agents
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Infectious Agents

Your genes, hormone changes, and aging are the most common causes of hair loss. But some infections and infection-related conditions can also leave you with bald patches or thinning strands. Most of the time, your hair will grow back after the infection heals. Sometimes, though, an infection can lead to permanent hair loss. Knowing the causes can help you seek the right treatment and prevent further damage. 

Ringworm: Contagious and Itchy
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Ringworm: Contagious and Itchy

Ringworm is a fungal infection causing round bald spots that are scaly, red, and itchy, and may be accompanied by a fever. The more the infection spreads, the bigger the bald spot will get. If left untreated, ringworm can cause permanent bald spots. It's highly contagious, especially among children. Treatment involves antifungal medications and medicated shampoos.

Folliculitis: Inflamed Hair Follicles
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Folliculitis: Inflamed Hair Follicles

Folliculitis is an infection of injured hair follicles, from activities such as shaving. It appears as pimple-like sores and itching. While many cases are mild, serious infections can damage follicles and cause permanent hair loss. Treatment may include antibiotics or antifungal treatments.

Seborrheic Dermatitis: Itchy and Flaky Scalp
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Seborrheic Dermatitis: Itchy and Flaky Scalp

Seborrheic dermatitis, linked to yeast fungus rather than infection, causes skin irritation and temporary hair loss around oily parts of your body. Symptoms include itchy, flaky scalp. Treatment typically involves medicated shampoos and topical treatments.

Piedra: Hard Nodules on Hair
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Piedra: Hard Nodules on Hair

Piedra is a rare fungal infection affecting the hair shaft, resulting in hard nodules. Though often asymptomatic, it can weaken hair and cause breakage. Treatment includes shaving the hair and antifungal medications.
 

Diagnosis and Treatment: Early Intervention
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Diagnosis and Treatment: Early Intervention

Early diagnosis and treatment are crucial for infections causing hair loss. Consult a health care provider for testing and tailored treatment options. Timely medical intervention can prevent permanent hair loss.

This content was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.