There are a small number of sexually transmitted infections that can cause hair loss, though it's a far less common cause than genetics, hormones, or everyday stress. Secondary syphilis is the condition most clearly linked to hair loss, and a few other infections can contribute indirectly through the body's broader immune response. I bring this up carefully with patients, since it's an uncommon cause but an important one not to miss when the pattern fits.
Key Takeaways
- Secondary syphilis is the STD most directly linked to hair loss, causing a distinctive patchy pattern sometimes described as "moth-eaten."
- HIV can contribute to hair loss indirectly, through the immune system's broader effects on the body rather than a direct attack on follicles.
- STD-related hair loss usually appears alongside other symptoms, such as a rash, sores, or systemic illness, rather than as an isolated symptom.
- This type of hair loss is generally treatable and often reversible once the underlying infection is properly diagnosed and treated.
- Testing is the only reliable way to confirm or rule out an STD as the cause, since the hair loss pattern alone isn't a definitive diagnosis.
Secondary Syphilis and Hair Loss
Syphilis is the sexually transmitted infection most clearly associated with hair loss. During its secondary stage, which typically develops weeks to months after the initial infection, some people develop a distinctive pattern of patchy hair loss, often described as "moth-eaten" because of the irregular, scattered bald patches across the scalp. Eyebrows and eyelashes can also be affected.
This happens because the infection triggers inflammation that disrupts the normal hair growth cycle. The good news is that this type of hair loss typically resolves once syphilis is treated with antibiotics, usually within a few months as the hair growth cycle recovers.
HIV and Hair Changes
HIV doesn't directly attack hair follicles the way syphilis does, but it can contribute to hair loss and texture changes through its broader impact on the immune system and overall health. Chronic illness, nutritional changes, and the physical stress of managing a serious infection can all push more hair follicles into a resting phase, similar to the shedding pattern seen with other significant illnesses.
Certain medications used to manage HIV have also been associated with hair changes in some patients, which is worth discussing with a doctor if you notice new shedding after starting a treatment regimen.
Signs That Point to an Infection Rather Than a Typical Cause
A few clues suggest an infection might be worth ruling out:
- Hair loss with an irregular, patchy pattern rather than the more predictable pattern seen in androgenetic alopecia.
- Hair loss accompanied by a rash, sores, swollen lymph nodes, or flu-like symptoms.
- A recent history of potential exposure alongside new or unusual symptoms.
- Hair loss affecting eyebrows or eyelashes along with the scalp, which is less typical of common causes like pattern baldness.
If none of these apply, a sexually transmitted infection is unlikely to be behind your hair loss, and more common causes are worth investigating first.
Getting Tested and Treated
If you have any reason to suspect an STD based on your symptoms or exposure history, testing through a doctor or a telehealth provider is the only way to know for sure. Syphilis is diagnosed with a blood test and treated effectively with antibiotics, and the associated hair loss typically improves once the infection clears.
Catching and treating the underlying infection promptly matters for more than hair loss. Untreated STDs, syphilis in particular, can lead to more serious health complications over time, which makes testing worthwhile regardless of what's happening with your hair.
Supporting Hair Recovery Afterward
Once you treat the underlying infection, hair typically grows back on its own as the follicles recover and re-enter their normal growth cycle. Keeping the scalp healthy during that recovery period can help. Our RootMD Hair Growth Oil is formulated with saw palmetto, pumpkin seed oil, and rosemary oil to support a healthy scalp environment as regrowth continues.
If your hair loss doesn't match this pattern or you're not sure what's causing it, my article on hair thinning versus balding covers the more common causes worth ruling out first.
