Infections That Cause Hair Loss

Infections That Cause Hair Loss

Hair loss can be defined as the recession or loss of hair from any part of the body, most often the scalp of the head. Although it is often caused by increasing age and changes in hormones, hair loss can also be brought on by infection of the skin, scalp, or hair follicles. Infections known to contribute to hair loss include ringworm, folliculitis decalvans, seborrheic dermatitis, scalp psoriasis, white piedra, and black piedra. In the following article we discuss common infections that can cause hair loss. 

What is Hair Loss?

Hair loss refers to the recession or loss of hair from any part of the body, most commonly the scalp of the head. Hair loss can be the result of aging, hereditary conditions, hormonal changes, medical conditions, or infection. Although hair loss is more common in men due to male pattern baldness, many women also experience some form of hair loss during their life. 

What Causes Hair Loss? 

Most hair loss is caused by increasing age and hereditary conditions. As the body ages, it becomes less efficient at processing and utilizing key nutrients, including iron, which helps keep red blood cells healthy to carry oxygenated blood to the scalp and hair. In old age, hair strands become smaller, thinner, and lose pigment. 

Hair loss can also be initiated by hormonal changes, stress, and infections. Traumatic events such as illnesses and accidents can cause a form of hair loss known as Telogen Effluvium. If hair loss is not caused by aging, hormonal changes, injury, or accident, it may be the result of an infection. There are many infections that cause hair loss, some of which affect the scalp, and some of which damage the hair follicles themselves. 

Infections That Cause Hair Loss

Most infections that cause hair loss are initiated by overgrown bacteria, yeast, or fungi that invade and damage the scalp and hair follicles. Scalp and hair follicle infections are usually curable with the right antibacterial or antifungal treatment. Common infections that cause hair loss include ringworm, folliculitis decalvans, and scalp psoriasis.  


Ringworm is a common fungal infection that can develop anywhere on the body. Ringworm is caused by dermatophytes, fungi that live off of the keratin in hair and nails. It is especially common in children. Fortunately, ringworm is usually easily identifiable by the distinct red rings it leaves on the scalp and skin. Skin infected by ringworm is often red and inflamed, and may also become scabbed and blistered in more serious cases. 

A ringworm infection can seriously damage hair fibers, causing them to weaken and break easily. Ringworm usually begins as a small pimple on the scalp that progressively expands, leaving patches of scaly skin and sparse hair. Eventually, the fungus infects the hair fibers, which leads to hair damage and hair loss. 

Folliculitis Decalvans

Folliculitis decalvans is a rare form of hair loss that usually affects the back of the scalp. Infection often results in irritation, sores, the appearance of pimple-like bumps, and mild hair loss. 

Folliculitis decalvans usually begins in adulthood and most often affects men and women in their 40s and 50s. It can contribute to the appearance of irregular white patches on the scalp, scalp lesions, and mild itching and pain. While there is no known cure for folliculitis decalvans, prescriptions medications can help to minimize scalp damage and scarring of the scalp. 

Seborrheic Dermatitis 

Seborrheic dermatitis is a skin condition that affects multiple areas of the body, most commonly the scalp. Infection usually results in the appearance of scaly patches of skin, red bumps, and dandruff. If developed on the scalp, seborrheic dermatitis can cause skin to become itchy and scaly, and damage hair follicles leading to hair loss. 

While there is a known link between seborrheic dermatitis and celtic genes, the exact cause of the condition is unknown. In serious cases, seborrheic dermatitis can make skin scaly, extremely itchy, and inflamed. This inflammation can cause the hair follicles to stop producing hair, and in some cases, never produce hair again. 

Scalp Psoriasis

A common skin disorder, scalp psoriasis affects an estimated 125 million people across the world. Those who have scalp psoriasis may have raised, red, scaly patches on their scalp or skin. Scalp psoriasis can appear as a single patch or in countless patches spread across the entire scalp or body. 

Scalp psoriasis can result in temporary hair loss. It is common for people with this condition to excessively scratch their scalp, resulting in hair loss in some cases. Medical professionals do not yet know of the exact cause of this condition, but doctors have theorized that it comes from an immune system defect that causes skin cells to grow too quickly and become raised patches on the skin. Scalp psoriasis is more likely to affect people who have family members that have also been infected. 

White Piedra

White piedra is a rare fungal infection caused by the fungus Trichosporon. White piedra is generally not contagious and most often affects young men and people who live in humid climates. 

The primary symptoms of white piedra include white nodules surrounding the hair shaft. These nodules are about 1 mm in diameter and are usually fairly easy to treat and remove. Serious infections of white piedra can cause hair to become brittle and break easily. It is advisable for people with white piedra to seek medical treatment if they find the infection causes pain or blistering. 

Black Piedra

While white piedra originates in Europe and the southern United States, black piedra is a scalp condition prevalent in tropical countries. Black piedra is an uncommon, persistent condition that  slowly wears away at the hair shafts. It often manifests as small black nodules on the scalp and hair shafts. Black piedra is brought on by the prevalence of a black yeast known as Piedraia hortae.  Severe infections of black piedra can cause the hair follicles to weaken and break, leading to hair loss. 

Can Fungal Infection Cause Hair Loss? 

Fungal infections can cause hair loss by severely weakening hair follicles, making it easy for them to break off. 

Infections That Cause Hair Loss: Summary

Common infections that cause hair loss include ringworm, folliculitis decalvans, seborrheic dermatitis, scalp psoriasis, white piedra, and black piedra. Most hair loss caused by infection can be treated through the use of antibacterial medication. 

Hair loss

Your medications, for less

Sale priceFrom $10.00
Sale priceFrom $10.00
Sale priceFrom $10.00