An infected ingrown hair typically looks like a swollen, red bump that has grown larger and more painful than a normal ingrown hair, often with a visible collection of yellow or white pus at its center. The surrounding skin may appear red, brown, or purple depending on your skin tone, and the area usually feels warm and tender to the touch.
Normal Ingrown Hair vs. Infected
A regular ingrown hair is a small bump, sometimes with a visible hair curled beneath the surface. It can be mildly irritating and slightly discolored, but it stays relatively small and tends to resolve on its own within a week or two. The key difference with infection is escalation: the bump gets noticeably bigger, the pain increases, and pus begins to form around the hair follicle.
Here’s what to compare:
- Size: A normal ingrown hair is a small papule, roughly the size of a pinhead. An infected one swells beyond that, sometimes reaching the size of a pea or larger.
- Color: Uninfected bumps cause mild skin discoloration. Infected bumps develop a pronounced red, brown, or purple halo with a white or yellowish center where pus has collected.
- Pain: Mild itching or tenderness is normal. Throbbing pain that worsens over a day or two signals infection.
- Pus: No pus in a standard ingrown hair. A pus-filled head (called a pustule) is the hallmark visual sign of infection.
What Causes the Infection
When a hair curls back into the skin instead of growing outward, it creates a small wound at the follicle. Bacteria that normally live on your skin, most commonly staph (Staphylococcus aureus), can enter through that opening and multiply. Shaving, waxing, or tight clothing can worsen the problem by adding friction and micro-tears to skin that’s already irritated. People with curly or coarse hair are more prone to ingrown hairs in the first place, which raises the overall risk of infection.
How It Looks in Different Areas
Infected ingrown hairs appear most often in areas you shave or where clothing creates friction: the face and neck (especially along the jawline in people who shave their beards), the bikini line, the underarms, and the legs. The basic appearance is the same everywhere, a swollen, pus-filled bump, but context matters. In the pubic area, an infected ingrown hair can closely resemble a genital herpes sore, which can cause unnecessary alarm. If you’re unsure whether a bump near your genitals is an ingrown hair or something else, the presence of a visible trapped hair beneath the skin and a single isolated bump (rather than a cluster of small blisters) points more toward an ingrown hair.
On the face and neck, infected ingrown hairs sometimes appear in clusters after shaving, creating a rash-like pattern of irritated, pus-filled bumps. This is essentially folliculitis, an infection of multiple hair follicles at once.
When It Progresses to Something Deeper
Most infected ingrown hairs stay superficial. But if the infection moves deeper into the skin, the bump can develop into a boil (also called a furuncle). A boil looks different from a surface-level infected ingrown hair: it’s a firm, warm lump deeper under the skin, often the size of a marble or larger, with pus collecting in its center. Over several days, a boil may develop a whitish or bloody fluid that leaks from the surface. Boils are more painful and take longer to resolve than a typical infected ingrown hair.
In rare cases, multiple boils can connect beneath the skin to form a carbuncle, a larger, deeper mass with several pus-filled heads. Carbuncles sometimes cause fever and fatigue because the infection is putting more strain on your body. Staph bacteria are responsible for most boils and carbuncles.
Warning Signs of Spreading Infection
An infected ingrown hair that stays contained in a small bump is manageable. What you want to watch for are signs that the infection is moving beyond the original site into the surrounding tissue, a condition called cellulitis. The visual cues are distinct:
- Expanding redness: The red or discolored area around the bump keeps growing over hours or days, rather than staying in a tight circle.
- Red streaks: Lines of redness radiating outward from the bump, following the path of nearby lymph vessels.
- New blisters: Fluid-filled blisters forming on the skin near the original bump.
- Fever or chills: A sign that bacteria may have entered your bloodstream.
Rapidly spreading redness, a high fever, a fast heart rate, or confusion are signs of a serious systemic infection and require urgent medical care. These complications are uncommon from a single ingrown hair, but they can happen when infections go untreated, especially in people with weakened immune systems or diabetes.
What to Do About It
A mild infection, one small pus-filled bump without spreading redness, often resolves with basic home care. Applying a clean, warm compress for 10 to 15 minutes several times a day can help draw the trapped hair closer to the surface and encourage the pus to drain naturally. Keep the area clean, avoid shaving over it, and don’t squeeze or dig at the bump with tweezers or needles. Breaking the skin with unsterilized tools can push bacteria deeper and make the infection worse.
If the bump keeps growing, becomes very painful, doesn’t improve after several days of warm compresses, or develops any of the spreading warning signs described above, a healthcare provider can assess whether you need a topical or oral antibiotic. For larger collections of pus, like a boil that won’t drain on its own, a provider may need to make a small incision to release the fluid. This is a quick in-office procedure that typically provides immediate pain relief.
To reduce the chance of future infections, exfoliate gently before shaving, use a sharp single-blade razor, shave in the direction of hair growth, and moisturize afterward. If you get frequent ingrown hairs in the same area, switching to a different hair removal method (or stopping removal altogether) is the most effective prevention.