Cold sores are a common and often frustrating skin issue. While they may look like harmless blisters, cold sores are actually caused by the herpes simplex virus (HSV).

What Causes Cold Sores?

Cold sores are caused by the herpes simplex virus (HSV), which comes in two types: HSV-1 and HSV-2.

HSV-1 is the primary cause of cold sores, usually appearing around the mouth.

HSV-2 generally causes genital herpes but can also lead to cold sores.

While the appearance of cold sores caused by both HSV-1 and HSV-2 can look similar, their locations tend to differ. However, it is possible for HSV-1 to cause sores on the genitals and for HSV-2 to appear on the mouth.

How Do Cold Sores Spread?

Cold sores are highly contagious and can spread easily. The virus can be passed on through:

• Kissing or skin contact
• Sharing food, drinks, or cosmetics (such as lip balm)
• Oral sex, which can spread both cold sores and genital herpes

Even when a cold sore isn’t visible, the virus can still be spread through close contact. This makes prevention and management key to reducing outbreaks and the risk of infecting others.

Once someone contracts HSV, it stays in the body for life. While the virus remains dormant most of the time, it can reactivate and cause new sores, especially during periods of:

• Stress
• Illness
• A weakened immune system

Unfortunately, there’s no cure for the herpes virus, but the symptoms can be managed.

Symptoms of Cold Sores

Cold sores don’t just appear out of nowhere. Before the sore is visible, you may notice a tingling or burning sensation around the lips or face, which can occur several days before the sore forms. This is the best time to begin treatment to shorten the outbreak.

When a cold sore does appear, it often looks like a red, raised blister filled with fluid. The blister can be painful to touch, and there may be more than one. Cold sores usually last around two weeks and are contagious until they crust over and heal.

The Five Stages of a Cold Sore

Cold sores go through distinct stages as they develop and heal:

• Tingling and itching: You may feel these symptoms about 24 hours before the blister appears.
• Blisters: Small, fluid-filled blisters form, typically around the mouth.
• Bursting: The blisters burst and form painful sores.
• Scabbing: The sores dry out, scab over, and may itch or crack.
• Healing: The scab falls off, and the cold sore heals.

Risk Factors for Cold Sores

Certain factors can trigger the reactivation of HSV, leading to cold sores. These include:

• Infection, fever, or cold
• Sun exposure
• Stress
• Menstruation
• Dental work or injury
• Weakened immune system due to conditions like HIV/AIDS, eczema, or chemotherapy

Managing and Treating Cold Sores

There’s no cure for cold sores, but several treatments can ease the symptoms and help manage outbreaks.

Topical Ointments and Creams

Over-the-counter antiviral creams like docosanol (Abreva) or prescription ointments like penciclovir (Denavir) can help reduce the duration of an outbreak, especially if applied at the first sign of a cold sore.

Oral Medications

Prescription antiviral medications like acyclovir, valacyclovir, and famciclovir can also help, particularly for people who have frequent or severe outbreaks. Your doctor may recommend taking these medications regularly to prevent future outbreaks.

Home Remedies

There are also some home remedies that may provide relief, such as:

• Applying ice or a cold washcloth to the sore
• Using aloe vera gel or lemon balm lip balms
• Applying petroleum jelly to ease discomfort

Canker Sores vs. Cold Sores: What's the Difference?

While cold sores and canker sores may seem similar, they are quite different:

Cold sores are caused by the herpes virus, appear around the mouth, and are contagious.

Canker sores are not contagious and appear as ulcers inside the mouth or throat.

Preventing the Spread of Cold Sores

To avoid spreading cold sores:

• Wash your hands frequently
• Avoid close contact with others during an outbreak
• Don’t share food, drinks, or personal items like lip balm

Cold sores can be a persistent issue, but with proper care and management, you can reduce the frequency of outbreaks and prevent spreading the virus to others.

Actress Jenny McCarthy has opened up about the lasting effects of her battle with mold poisoning, revealing that the experience has left her with post-traumatic stress disorder (PTSD), anxiety and a fear of being exposed to mold again.

During a recent episode of her podcast, The Jenny McCarthy-Wahlberg Show, the actress spoke about the physical and emotional toll of the illness, the extensive measures she has taken to avoid further exposure and her ongoing recovery.

McCarthy said she had to discard most of her belongings after the suspected exposure, including her clothes and furniture.

"I wound up throwing everything away," she said, adding that she and her husband, Donnie Wahlberg, also left their furniture behind when they moved out of their Los Angeles home.

Although she believes the exposure may have originated in her makeup room, she said she did not want to take any chances.

Jenny McCarthy Says Mold Poisoning Left Her With PTSD

Also read: One In Three Hospital Patients With Serious Mould Infections Died, CDC Study Finds

McCarthy said the experience made her fearful of encountering mold wherever she went. She described having histamine reactions in different places and struggling with everyday activities, including travelling in Ubers, visiting restaurants and boarding airplanes.

The actress also revealed that the prolonged health struggles contributed to a nervous breakdown, leaving her husband worried about her well-being.

Having undergone 11 surgeries in 15 months, McCarthy said she became increasingly afraid that her body would start "falling apart again."

She also described the emotional strain of her treatment, which involved taking around 100 pills a day.

"I find myself crying sometimes," she said, describing how difficult it was to manage the medication and the uncertainty surrounding her recovery.

Jenny McCarthy's Symptoms And Mycotoxin Poisoning Diagnosis

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McCarthy first spoke publicly about her health ordeal in March, describing six months of what she called "living hell."

She previously reported experiencing an infected root canal, pus-filled growths on her eyelids, mouth infections, tooth pain, skin rashes and food allergies.

The actress said a doctor diagnosed her with mycotoxin poisoning in December 2025. She has since described being in remission for seven months and focusing on recovery.

Her efforts to avoid further exposure have also been extensive. In an October 29 podcast episode, she revealed that she had been sleeping in a tent in her backyard because she was afraid of being exposed to mold indoors.

"Because I am paranoid now about basically sleeping anywhere, I live in a tent," she said.

McCarthy has also spoken about concerns over her breast implants and whether they could be associated with mold exposure. During a November 3 podcast episode, she discussed the issue with plastic surgeon Dr Terry Dubrow, who has treated her previously.

What Is Mycotoxin Poisoning And How Can It Affect Health?

Mycotoxins are toxic substances produced by certain molds and other fungi. Exposure can occur through contaminated food or environments, depending on the type of toxin and the route of exposure.

According to the Cleveland Clinic, mycotoxin exposure can affect different parts of the body, including the digestive system, eyes and mouth. Mold exposure can also trigger allergic reactions and worsen respiratory conditions such as asthma.

The health effects depend on factors such as the type of mycotoxin, the amount and duration of exposure, and an individual's susceptibility.

In a bizarre medical case, a 28-year-old US man began seeing his pet cat Luna’s features on human faces after brain surgery. These included almond-shaped eye sockets enlarged pupils and stripes.

If Karl sees Luna first thing in the morning, he continues to see her features on human faces throughout the day, whether in person or online.

However, if he wakes up looking at a human face, he may see that person’s pupils and eye shape on other people’s faces and even on his cat.

According to a case report published in the journal Cortex, Karl experiences a form of palinopsia, in which something seen earlier persists or reappears in subsequent perception. In his case, this causes facial distortions known as prosopometamorphopsia (PMO).

How Did The Condition Begin?

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Karl, who lives in the northeastern US, has experienced the condition for two years. It began after surgery to remove part of his right temporal lobe to treat an arteriovenous malformation (AVM), an abnormal tangle of blood vessels connecting arteries and veins that can cause bleeding in the brain.

The right temporal lobe plays an important role in face processing.

"This case of Karl seeing his cat's features in human faces and vice versa demonstrates that individual features can be pulled from memory and influence our ongoing perception," said lead author Brad Duchaine, professor and chair of psychological and brain sciences and principal investigator of the Social Perception Lab at Dartmouth.

More Than 250 People Experience Facial Distortions

Karl is not alone. According to Duchaine's lab, more than 250 people experience facial distortions. Many are mistakenly diagnosed with psychiatric problems.

"We have heard from people who have been told that they had a psychiatric problem and, in some cases, have even been put on antipsychotics, when they are in fact just having visual problems," Duchaine said.

Duchaine also cited a 1986 study published in Cortex. It described a woman who saw a poodle sitting on a passenger's lap while riding a bus. She then began seeing the poodle's face on every passenger. The woman had experienced a stroke nine months earlier.

Unlike that case, Karl sees individual facial features transferred between faces rather than entire faces.

How AI Can Help

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Duchaine used a large language model to turn a line drawing of Karl’s experience into a photorealistic image. He then worked with Karl to refine the visuals featured in the report.

AI-generated images can help researchers understand visual distortions and help patients explain their experiences to doctors, friends and family, Duchaine said, adding that he will continue working with Karl to decode more about the condition.

What Is Prosopometamorphopsia?

Prosopometamorphopsia (PMO) is a rare visual condition in which faces or facial features appear distorted due to changes in the brain's face-processing network. The term combines prosopo (Greek for face) and metamorphopsia (perceptual distortion).

People with PMO may see facial features as:

• Droopy or stretched

• Larger or smaller than normal

• Displaced or out of position

• Distorted in specific parts of the face

Two prominent subtypes are:

• Full-face PMO: The entire face appears distorted

• Hemi-PMO: One half of the face appears distorted

Most cases last days or weeks, although some persist for years. Around 75 case reports have so far been published.

Rubbing your eyes is a common habit, often triggered by itching, dryness or tiredness. However, frequent and vigorous rubbing can damage the cornea and increase the risk of keratoconus, a progressive condition that causes it to thin and bulge outward, experts warn.

World Keratoconus Day is observed every year on November 10 to raise awareness about the condition.

Early diagnosis is important to slow its progression. Frequent changes in spectacle prescriptions or deteriorating vision should prompt an eye examination.

Why Should You Avoid Rubbing Your Eyes?

Frequent or aggressive eye rubbing can put mechanical stress on the cornea, potentially weakening its structure and worsening existing eye conditions.

Speaking to HealthandMe, Dr Janhvi Mehta, Consultant Ophthalmologist, Jaslok Hospital and Research Centre, Mumbai, said, "Frequent or vigorous eye rubbing can damage the cornea, particularly by contributing to keratoconus. It can also cause corneal epithelial injury and worsen existing ocular allergy."

Repeated rubbing can:

• Contribute to corneal thinning and biomechanical weakening.
• Accelerate keratoconus in susceptible individuals.
• Cause corneal abrasions and increase the risk of infection.

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Dr Mahipal Singh Sachdev, Chairman and Managing Director, Centre for Sight Group of Hospitals, explained that excessive rubbing puts pressure on the cornea and can damage its collagen structure.

"The cornea might become thinner than usual or its shape may become uneven, leading to impaired vision. Hence, people should avoid the habit of rubbing their eyes," he told HealthandMe.

Why Are Children More At Risk?

Children with allergies, especially allergic conjunctivitis, may be more vulnerable to keratoconus because of frequent eye rubbing.

Allergies can cause persistent itching, redness, watering, and discomfort, encouraging children to rub their eyes repeatedly. The resulting mechanical stress may contribute to the development or progression of keratoconus in susceptible individuals.

The experts urged parents to watch for excessive rubbing and changes in their children's vision. Timely allergy treatment and regular eye examinations can help identify potential problems early.

Other risk factors for keratoconus include:

• Vernal keratoconjunctivitis (VKC)
• Atopic eye disease
• Family history of keratoconus
• Genetic predisposition
• Certain connective tissue disorders

However, not everyone who frequently rubs their eyes develops keratoconus.

Read More: 6 Million People In Delhi Living With Poor Vision: AIIMS Study

Why Is Keratoconus Often Diagnosed Late?

Dr Janhvi noted that keratoconus commonly begins during adolescence or early adulthood but may remain undiagnosed until vision deteriorates.

Its early symptoms can resemble common refractive errors such as myopia. Children and young adults may experience mild blurring or require frequent changes in their spectacle prescriptions, which can be mistaken for routine vision changes.

The condition can also progress gradually and initially affect only one eye, making changes harder to recognise. Routine eye examinations may not always detect early keratoconus without specialised corneal assessment, Dr. Mahipal said.

Warning signs to watch for include:

• Increasing myopia
• Progressive or irregular astigmatism
• Frequent changes in spectacle prescriptions
• Reduced visual clarity despite corrective lenses
• Ghosting, glare or double vision in one eye
• Difficulty driving at night

Increasing astigmatism despite repeated spectacle corrections is an important warning sign that warrants further evaluation.

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How Can You Prevent Corneal Damage?

Preventing excessive eye rubbing and managing its underlying causes can help reduce avoidable stress on the cornea.

1. Break the eye-rubbing habit

• Avoid pressing or massaging closed eyelids.
• Use a cold compress when your eyes itch.
• Avoid rubbing your eyes even through a towel or handkerchief.
• Keep children's fingernails short to minimise accidental injury.

2. Treat underlying allergies

If itching triggers eye rubbing, consult an ophthalmologist about appropriate treatment. Options may include topical antihistamine or mast-cell stabiliser drops, such as olopatadine or ketotifen.

Other measures include:

• Using preservative-free artificial tears for irritation
• Treating associated blepharitis or dry eye
• Avoiding prolonged use of topical steroid drops without medical supervision

3. Reduce exposure to environmental triggers

• Avoid dust, smoke and known allergens
• Wear protective glasses outdoors
• Avoid direct airflow from air conditioners.