HIV produces a range of visible changes inside the mouth, from white patches and red gum lines to dark spots and painful sores. These oral signs often appear before other symptoms and can be one of the earliest clues that the immune system is struggling. Most HIV-related oral conditions show up when the immune cell count (CD4 cells) drops below 200 per microliter, though some appear earlier. When CD4 counts stay above 500, oral lesions are rare.
White Patches: Oral Thrush
The most common oral sign of HIV is candidiasis, better known as thrush. It takes three main forms, each with a distinct look.
Pseudomembranous candidiasis is the classic version: creamy white, curd-like patches that coat the inner cheeks, tongue, and roof of the mouth. These patches are soft or gelatin-like and can be scraped off with a finger or tongue depressor. Underneath, the tissue is red, raw, and sometimes bleeding. The surface is often painful.
Erythematous candidiasis looks quite different. Instead of white patches, it shows up as flat red areas, typically on the roof of the mouth and the top surface of the tongue. It’s easy to miss because it blends in with surrounding tissue, but the redness is persistent and may cause a burning sensation when eating spicy or acidic foods.
The third form, hyperplastic candidiasis, produces white plaques that look similar to the first type but cannot be wiped away. These firm patches most often appear on the inner cheeks and tend to persist longer. Because they don’t scrape off, they can be confused with other white lesions in the mouth.
Hairy Leukoplakia on the Tongue
Oral hairy leukoplakia is one of the most distinctive HIV-related mouth changes. It appears as white, thickened patches along the sides of the tongue, either on one side or both. The surface texture sets it apart: it can look flat, vertically ridged, or almost fuzzy, which is where the name “hairy” comes from. Unlike thrush, these patches don’t scrape off.
Hairy leukoplakia is painless and caused by the Epstein-Barr virus, which reactivates when the immune system weakens. It rarely appears anywhere else in the mouth besides the tongue’s side edges. While it doesn’t cause direct harm, its presence is a strong signal of significant immune suppression. With effective HIV treatment, these patches typically shrink or disappear entirely.
A Red Line Along the Gums
Linear gingival erythema, once called “HIV-associated gingivitis,” creates a distinctive fiery red band running along the gum line. The band is typically 2 to 3 millimeters wide and most visible around the front teeth. What makes it unusual is that the redness is completely out of proportion to the amount of plaque on the teeth. Even in someone with good oral hygiene, the bright red strip persists. The gums bleed easily but don’t show the typical signs of gum disease like receding tissue or deep pockets between the teeth and gums.
This redness sometimes extends beyond the gum line into the surrounding tissue. Standard dental cleaning doesn’t resolve it, which is what distinguishes it from ordinary gingivitis. It responds better to antifungal treatment, since it’s driven by yeast organisms rather than the bacteria that cause typical gum inflammation.
Dark or Colored Spots on the Palate
Kaposi Sarcoma
Kaposi sarcoma is a type of cancer closely linked to advanced HIV. In the mouth, it most often appears on the hard and soft palate (the roof of the mouth), the gums, and the top of the tongue. Early lesions may look like flat, painless discolorations ranging from brownish-red to deep purple. Over time, they can grow into raised plaques or bulky masses that interfere with chewing and swallowing. The color varies: some are barely pigmented, while others are strikingly violet. Any unexplained dark or reddish patch on the roof of the mouth that doesn’t go away warrants prompt evaluation.
Melanin Hyperpigmentation
HIV can also cause dark brown spots or patches inside the mouth that are not cancerous. These painless marks can appear anywhere on the oral tissue and range from light tan to deep brown. They vary in size and shape, sometimes appearing as a single spot and other times scattered across the cheeks, gums, or palate. The cause isn’t fully understood, but it likely involves a combination of immune system disruption, hormonal changes affecting the adrenal glands, and HIV medications themselves. Studies suggest that people on antiretroviral therapy actually have a higher rate of this pigmentation than those not yet on treatment, so the medications may play a role.
Mouth Ulcers and Sores
Painful ulcers resembling canker sores occur frequently in people with HIV. These round or oval sores have a white or yellowish center surrounded by a red border. They can appear on the inner lips, cheeks, tongue, or soft palate. In HIV, these ulcers tend to be larger, more painful, and slower to heal than ordinary canker sores. They sometimes appear during acute HIV infection (the first weeks after contracting the virus) as part of a flu-like illness, then return later as the immune system declines. Effective antiviral treatment reduces both their frequency and severity.
Swollen Salivary Glands and Dry Mouth
HIV can cause the major salivary glands, especially the ones in front of the ears (parotid glands), to swell. This shows up as a soft, diffuse puffiness on one or both sides of the face that can be noticeable enough to change facial appearance. The swelling may come with pain or simply feel like fullness in the cheeks. In some populations, salivary gland disease affects nearly half of people living with HIV.
Dry mouth often accompanies the swelling, since the glands aren’t functioning normally. Persistent dryness increases the risk of tooth decay and makes eating and speaking uncomfortable. Both the swelling and dryness can improve with HIV treatment, though some antiretroviral medications contribute to dryness as a side effect.
How These Signs Track With Immune Health
The oral signs of HIV don’t appear randomly. They follow a pattern tied to how suppressed the immune system has become. When CD4 counts are above 500 cells per microliter (the normal range), oral lesions are essentially absent. As counts drop below 200, the mouth becomes a visible map of immune decline: thrush, hairy leukoplakia, gum disease, and ulcers all become far more common. In a large cross-sectional study, most patients with oral lesions had CD4 counts below 200.
This is one reason dentists sometimes spot HIV before a physician does. Oral changes can precede other symptoms by months or even years. The good news is that antiretroviral treatment dramatically reduces the occurrence of nearly all these conditions. Studies consistently show that as the virus is controlled and CD4 counts recover, thrush, hairy leukoplakia, and ulcers improve or resolve. The mouth, in effect, becomes one of the clearest windows into how well treatment is working.