Nummular headache is a rare condition that causes a coin-sized area of pain on the scalp and tenderness of the surrounding area.

Nummular headache is a very rare but possibly underdiagnosed primary headache disorder. Only a few hundred cases have ever been described in scientific literature, so there’s limited research in the area.

The most unique feature of a nummular headache is that the painful area is the shape and size of a coin. Unlike other headache types, nummular headaches don’t affect the forehead. Instead, they occur in an area of the scalp, under your hair.

Read on to learn more about how doctors diagnose nummular headache disorder and what treatments have shown promise for the condition.

Nummular headache is a rare headache disorder. It causes pain in one very localized area of your scalp.

Someone with a nummular headache can point directly to the location of the pain. The area normally measures 1 to 6 centimeters in diameter. It’s sometimes called a “coin headache” because it’s usually circular or oval-shaped.

Nummular headache was first described by researchers in 2002. It’s also very rare, which means there’s a lot we don’t understand about it. But it may be an underreported condition because many people don’t seek care for the problem.

Nummular headache disorder isn’t generally caused by another condition or disorder, which makes it a primary headache disorder like migraine and cluster headache.

The primary symptom of a nummular headache is pain on the scalp in a unique coin-sized area.

The pain feels like pressure, stabbing, or burning. The pain is typically of mild to moderate intensity, but it can be severe in some cases. The pain can come and go, or it can be constant.

Going by two very small studies, nummular headaches often last less than 30 minutes, but they can come back several times per day.

They may also appear every other day or at random for several weeks in a row, followed by a symptom-free period. Some cases have shown pain that is unrelenting without treatment.

Nummular headaches can cause other symptoms too, including pain and sensitivity in the surrounding area. These changes in sensitivity, called allodynia, can make ordinary touch very uncomfortable or painful.

Other sensory changes that may happen include:

  • a change in touch sensation (dysesthesia)
  • a burning or prickling sensation (paresthesia)
  • decreased sensation (hypoesthesia)

Although the coin-shaped area most often occurs in one spot, nummular headache can also cause more than one coin-shaped area of pain.

The headache can be on any part of the head, but it’s most common around the middle, under your hair.

Nummular headache doesn’t cause symptoms typical of other headache disorders like migraine. It doesn’t come with nausea, vomiting, or light and sound sensitivity. It also doesn’t cause tearing or runny nose like a cluster headache does.

Nummular headache is a primary headache disorder, which means that it’s not the result of an underlying injury or condition, like a tumor or abscess.

Research has suggested that it’s of neurological origin. However, other factors have been shown to affect the condition, such as hormonal changes during the menstrual cycle.

Researchers have also speculated it may be connected to autoimmune conditions. Another potential risk factor may be a history of other headache disorders.

One observational study from 2019 found that 29 people out of 225 with the diagnosis had head trauma just before pain onset.

A 2020 analysis of 110 cases of nummular headache reported these characteristics in people with the condition:

  • most common in middle age, with average age of 47 years
  • more common in women than men, by ratio of 1.5 to 1

Nummular headache is diagnosed by taking a medical history. The doctor will ask about your symptoms to see whether they align with this rare condition.

The doctor may also do tests, including:

Before determining that you have nummular headache, a clinician will make a differential diagnosis to rule out other types of headaches, such as migraine and tension headache.

Although nummular headache can happen at the same time as migraine or tension headache, the two diagnoses are not related.

Treatment for nummular headaches includes pain relief and preventive measures.

To relieve pain, doctors may recommend:

  • nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or naproxen
  • analgesics, such as acetaminophen, aspirin, and prescription pain medication

If these aren’t helping or if your nummular headache returns, doctors may recommend preventive strategies, such as:

Botulinum toxin A (Botox) has also relieved nummular headache symptoms in some individuals.

Nummular headache was first identified in 2002. It’s a primary headache disorder where the pain isn’t the result of another condition.

To diagnose nummular headache, a clinician will look for symptoms of the disorder and also rule out other conditions such as migraine. The condition is considered rare and may be underdiagnosed.