Symptoms of Mpox

Mpox (formerly known as monkeypox) is a type of zoonotic viral disease (a virus that spreads from animals to humans). It was first identified in 1958 in monkeys being used for research. But monkeys aren't the only carriers of mpox—other animals, including rodents, can transmit the virus.

Humans can get mpox if an infected animal bites them or they come in contact with an infected animal's fur or bodily fluids. They can also get it from close contact with an infected person. 

The mpox virus is from the same family of viruses that causes smallpox. Many mpox symptoms are similar to smallpox but milder. Mpox is rarely fatal. The most common symptoms of mpox are fever and chills, headache, lethargy, muscle and joint pain, fatigue, swollen lymph nodes, and rash. 

This article will cover the most common symptoms of mpox, less common ones, complications, and when to see a healthcare provider. 

Frequent Symptoms 

While there are classic symptoms of mpox, it is possible to not experience all the signs.

Researchers found that in the 2022 outbreak, many cases did not follow the general symptom patterns. This new presentation pattern includes fewer skin symptoms and the appearance of the skin symptoms before lymph node swelling, fever, or other symptoms.

Symptoms will start within three weeks of exposure. It is possible to test positive for the mpox virus and not have any symptoms.

Fever and Chills 

Fever and chills are part of an invasion period lasting from zero to five days. A study reported in 2022 found 62% of study participants experienced fever as an initial symptom. With fever, the body will start to feel cold as the temperature climbs, and you will experience shivers and chills.

Headache

Intense headache is another common symptom experienced during the invasion period for mpox. It might affect around 27% of people who contract the virus.

Lethargy 

Lethargy refers to a state of fatigue accompanied by a lack of physical and mental motivation. It affects around 41% of people who contract the mpox virus.

Muscle Aches and Joint Pain

People who experience a fever with mpox might also experience muscle aches and joint pain. Back pain and muscle pain are considered common symptoms that are part of the invasion period.

Fatigue

Fatigue is a common symptom of most viruses and illnesses, and mpox is no different. Fatigue with a viral disease causes a significant lack of energy and exhaustion that sleep and rest cannot immediately resolve.

Fatigue is expected as the body is fighting the mpox virus but will improve as you start to feel better and other symptoms dissipate.

Respiratory Symptoms

Some people experience upper respiratory symptoms with mpox. Respiratory symptoms might include sore throat, nasal congestion, or cough.

Swollen Lymph Nodes

Lymphadenopathy (swollen lymph nodes) is one of the most significant symptoms of mpox, affecting more than half the people who contract the virus. Lymph node swelling in mpox can occur in the neck, armpits, and groin on one or both sides of the body.

Skin Rash

After a few days of early symptoms, a rash will develop. This rash can vary in appearance, the number of lesions, and distribution.

It typically appears as flat, red bumps, developing over time into papules (raised bumps), vesicles (small fluid-filled blisters), and pustules (a bump containing pus) before drying up, scabbing over, and falling off. The rash can be painful and itchy.

Mpox sores can appear on the mouth, genitals, or anus. Some people might experience blisters on their hands and the soles of their feet.

Symptoms in Children 

Children seem to experience the same symptoms as adults. Infants, children under age 8, children with eczema and other skin conditions, and those with immunocompromising conditions may be at increased risk for sever disease when they contract mpox.

Most children will experience fatigue, headaches, difficulty swallowing, cough, and other classic symptoms. They can also have facial lesions near their eyes and eyelid crusting. 

How Long Will Symptoms Last?

The symptoms of mpox start within three weeks after exposure to the virus. If you develop flu-like symptoms, you will likely experience a rash within a few days. According to the Centers for Disease Control and Prevention (CDC), the entire course of the illness is from two to four weeks.

Rare Symptoms 

Mpox is recognizable by the type of rash it causes and the symptoms that occur before the rash appears. But some signs of the condition considered less common might affect smaller numbers of people. Rarer symptoms include eye and gastrointestinal symptoms. 

Eye Symptoms 

Some people who contract mpox will experience ophthalmological (eye-related) symptoms.

Mpox eye symptoms might include blepharitis (eyelid infection), conjunctivitis, focal conjunctival lesions (tumors of the conjunctiva, which is the mucous membrane covering the front of the eye and inside of the eyelids), corneal ulcerations (open sores on the cornea, which is the clear covering on the front of your eye), light sensitivity, keratitis (inflammation of the cornea), and vision loss.

According to a 2022 Nature report, ophthalmic manifestations are much rarer compared to other symptoms of mpox.

According to this report, eye symptoms linked to mpox include:

• Conjunctivitis (pink eye) and edema (swelling): Both symptoms will affect the eyelids of 20% of people with mpox. People with conjunctivitis had a higher frequency of other symptoms, including "nausea, chills/sweating, oral ulcers, sore throat, general malaise, lymphadenopathy [lymph node disease], and photophobia [eye pain in bright light]." This study also found that 47% of people with conjunctivitis from mpox reported being bedridden, compared to 16% who did not have conjunctivitis.
• Corneal involvement that ranged from mild to severe
• Corneal infections that lead to keratitis
• Corneal scarring 
• Permanent vision loss: One study found that unilateral or bilateral blindness and weak vision occurred in 10% of primary mpox cases (infection from an animal source) and 5% of secondary cases (person-to-person transmission).
• Blepharitis in 30% of unvaccinated cases

Gastrointestinal Symptoms

Gastrointestinal symptoms like nausea, vomiting, and diarrhea are not classic symptoms of mpox. But gastrointestinal symptoms can occur in some people with viral illnesses.

People who experience these symptoms might also have severe dehydration, which could, along with other severe symptoms of mpox, lead to electrolyte abnormalities (variation in the level of charged minerals in the blood, such as sodium and potassium) and shock (diminished blood flow to the organs and tissues).

Complications/Subgroup Indications 

Mpox can lead to severe complications, some of which might require hospitalization or more extensive treatment methods. Those at greater risk for severe disease include young children (under 8 years), individuals who are pregnant or immunocompromised, and individuals with history of atopic dermatitis or eczema.

Complications of mpox can include:

• Secondary skin infections
• Severe scarring on the face, arms, and legs
• Pneumonia (lung inflammation)
• Vision changes or blindness
• Proctitis (inflammation and sores inside the rectum) and urinary problems
• Death (rare)
  

An observational study reported in August 2022 in the journal Clinical Microbiology and Infection found that 36% of study participants had mpox complications. The most commonly observed complications were anal region pain and cellulitis (a skin infection).

Complications that required hospitalization included cellulitis, paronychia (nail infection), severe digestive and anal involvement, noncardiac angina (chest pain in people without heart disease), dysphagia (swallowing difficulty), blepharitis, and keratitis.

When to See a Healthcare Provider

People who have been in close contact with a person or animal with mpox should monitor their health for at least three weeks after exposure. You should check your body temperature daily.

If you develop a fever (100.4 or above), swollen lymph nodes, rash, or other mpox symptoms, self-isolate and contact a healthcare provider immediately. 

Mpox is rare in the United States. It is transmitted by close contact. If you develop a new rash, have symptoms of mpox, and think you have been exposed to the virus, you should reach out to a healthcare provider. 

Summary 

Mpox is a zoonotic viral disease, meaning it is transmitted from animals to humans. It also can be transmitted between humans. The mpox virus is related to the virus that causes smallpox. It can cause similar but mild symptoms. 

The most common symptoms of mpox are fever, headache, lethargy, muscle and joint pain, fatigue, swollen lymph nodes, and rash. Less common symptoms include severe eye symptoms and gastrointestinal symptoms.

Mpox can cause more serious problems considered complications, including nail and skin infections, noncardiac chest pain, problems with swelling, and inflammatory eye troubles. 

If you have been in close contact with a person or animal with mpox, you should monitor yourself for at least three weeks. If you develop symptoms, self-isolate and call a healthcare provider. 

A Word From Verywell 

For most people who contract mpox, the condition is mild and self-limiting. But it can be a serious disease, especially for immunocompromised children and adults (people who have a weakened immune system).

Most people recover fully from mpox, but some might experience severe complications. Therefore, it is crucial to seek medical help if you think you might have been exposed, especially for a child or anyone with an underlying health condition.