Dermatologists often get little or no training on diseases and conditions of the mouth — particularly the tongue — because
these problems tend to cross into specialties, such as maxillofacial surgery and ear, nose and throat.
But people with pigmentary, texture and other changes on the tongue often turn first to dermatologists for diagnoses and possible
treatment, says Janellen Smith, M.D., dermatologist, associate clinical professor, University of California, San Francisco
(UCSF) Medical Center, San Francisco.
Tongue anatomy 101 Knowing basic tongue anatomy is important. Dr. Smith says, the most notable elements of the tongue are:
- Papillae, which are on the tongue's dorsum. There are four types, including: filiform papillae, which is the little white
carpet of things that project upwards on the tongue, used to lick and move things to the back of the tongue; fungiform papillae,
which are the parts that dot across the surface of the tongue, are bright red and are concentrated along the edges and the
tip of the tongue; circumvallate papillae, of which there are only seven to 11 in the back of the tongue and they form a "V";
and foliate papillae, which are right at the tip of the V that forms the circumvallate papillae.
Historically, a signal of disease Two hundred years ago, people thought that one of the most important things that you could do when you examined a patient
was to have the patient stick out his tongue.
The filiform papillae would change and the thought was that they could interpret those changes to better understand what was
going on inside the body, according to Dr. Smith.
"It is true, to a certain degree, that you can do that," she tells Dermatology Times. "If someone is very ill the filiform papillae get thicker and become furred. This happens because each of the papillae has
keratin. If someone is eating normally and is healthy, the food that person eats takes off the top keratin layer, constantly
"dekeratinizing" the tongue. If someone is ill and they cannot eat, that does not happen."
Tongue conditions Dermatologists are among the first to see a host of tongue problems, many of which are not associated with illness but do
cause cosmetic concern.
One of the most common is fissured tongue. Patients might be born with fissured tongue, also referred to as scrotal tongue,
or develop it over time. The normal tongue has a smooth top at the back; a fissured tongue has deep fissures, one down the
middle and then fissures branching off to the side, according to Dr. Smith.
"It is mostly a cosmetic issue but sometimes it can get painful from food getting caught in the deep fissures," she says.
"If it is causing pain, patients probably need to cleanse their tongues better, and they can do so with a soft toothbrush
or rinse it with 1 percent or 2 percent hydrogen peroxide or mouthwash."
While, tongue pigmentation is uncommon, most areas of pigmentation on the tongue are from ethnic variations; so, people who
tend to be more pigmented on their skin tend to have more pigmentation in their mouths and sometimes on their tongues, according
to Dr. Smith.
The pigmentation might be regular or irregular and is usually not something to worry about; however, dermatologists should
biopsy any new area of pigmentation, according to Dr. Smith.
"Unfortunately, we do not have anything that we can do to de-pigment the tongue," she explains.
As people age, they might get caviar tongue, which occurs underneath the tongue or along its lateral edges. These patients
present with dilated blood vessels on the tongue called varices.
"On the tongue, they often have rounded shapes that make them look like little dots of caviar," she says. "These lesions do
not need to be treated and do not signal any underlying health issues."
Some conditions signal concern The tongue is often the site for choristomas, a condition where normal tissue is in an abnormal place.
"You can have on the back of your tongue little bits of brain or bony tissue or cartilage," Dr. Smith says.
While most of these are not clinically significant, there have been cases in which the tissue on the back of the tongue was
the patient's thyroid.
Babies are often born with the tissue on the backs of their tongues and as they grow the thyroid can make it hard to swallow
— even breathe.
"In some cases, the dermatologist would see this lump on the back of the tongue and cut it out. The problem is that for most
people with a lingual thyroid, that is all the thyroid they have," she says.
The first treatment strategy is usually to prescribe a thyroid medication that suppresses the thyroid and makes it smaller.
At times, thyroid removal is the only option.
Infectious diseases are common on the tongue. Although most people think of herpes simplex as affecting the tongue only on
the primary herpes gingivostomatitis, recurrent herpes simplex virus infection of the oral cavity, which usually occurs on
the lips, can occur on the tongue.
"When people come in with sores on their tongues, the most frequent cause is aphthous stomatitis," Dr. Smith says. "But if
you have sores above the lateral margin of the tongue, particularly on the dorsum, it is frequently herpes simplex."
Human papillomavirus (HPV) warts are becoming a more common occurrence on the tongue. One of the most common spots for HPV
on the tongue is on the lateral border, according to Dr. Smith.
"You can treat the warts with liquid nitrogen or use podophyllin, but have to be careful because if you consume too much podophyllin
you can get into trouble," she explains.
Treatment is important because some HPVs are oncogenic.
"We are seeing an increase in tongue cancer in younger age groups and one of the questions is could it be because we are seeing
more HPV?" Dr. Smith asks.
The same benign neoplasms that occur on the body, including fibromas, neurofibromas, lipomas, leiomyomas and dermoid cysts,
can occur on the tongue, as well.
"One thing we see on the tongue that is unusual elsewhere is a granular cell tumor," she says. "The most common spot on the
tongue to see these is on the lateral border. Granular cell tumors are usually not malignant, but there is a very rare malignant
variety and because of that, you have to take them off."
Squamous cell carcinoma The most common malignant neoplasm of the tongue is squamous cell carcinoma.
"These are rarely caught in their early stages," Dr. Smith admits. "Squamous cell carcinoma presents as a lump in the tongue,
sometimes with pain, but often not. Sometimes patients have difficulty swallowing. By the time it causes difficulty swallowing
or people notice it, it is usually pretty big. And the larger the tumor, the worse the outcome."
Squamous cell carcinomas occur most commonly along the lateral edge of the tongue. The cause of the cancers is not clear but
some experts suspect HPV, marijuana use or smokeless tobacco, especially among younger patients, according to Dr. Smith.
"Overall survival for tongue cancer is somewhere in the 50 percent to 55 percent range; although younger patients have a higher
survival rate for some unknown reason," Dr. Smith says. "The problem is in order to get the really small ones you really have
to examine the tongue well and get your hands in there and feel the tongue."
The treatment for tongue cancer is often glossectomy or partial glossectomy, where all or part of the tongue is removed. Radiation
is being used more frequently now to avoid this disfiguring treatment, according to Dr. Smith.
Basal cell carcinoma does not occur on the tongue, but in very rare cases melanoma does, according to Dr. Smith.
Dermatologists and others are not seeing as much Kaposi's sarcoma of the tongue as they used to, according to Dr. Smith. This
is because of more effective HIV therapies.
Skin diseases of tongue Diseases of the skin that occur in the mouth include pemphigus vulgaris, lichen planus, lupus, erythematosus and erythema
multiforme. Erythema multiforme has prominent features in the mouth and commonly presents orally. According to Dr. Smith,
patients will often get broad erosions of the tongue and other oral cavity surfaces.
Tongue jewelry and adornments, as well as tongue splitting, can cause havoc with the body, according to Dr. Smith. Complications
associated with tongue barbells, for example, include brain abscesses and endocarditis.
"Dermatologists are often at the front line in diagnosing diseases and conditions of the tongue and it is important that they
are aware of what can occur so that they can either treat patients or refer them to specialists," Dr. Smith says.
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