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.

For 25-year-old Kaela Knight, a nail artist from Colorado, taking tirzepatide, the active ingredient in Eli Lilly's Mounjaro and Zepbound, brought an unusual side effect: skin so sensitive that even a light touch hurt.

Knight started treatment in September 2024 at 210 pounds and eventually reached 125 pounds. But during her second month, as her dose increased from 2.5 mg to 5 mg, she began experiencing burning sensations.

"I always describe it as feeling like a sunburn without any visible redness or irritation," she told the Daily Mail.

The sensation affected her hips, forearms and neck. Episodes lasted 24–48 hours, although some persisted for about a week.

Other patients taking Novo Nordisk's Ozempic and also Mounjaro have reported similar experiences.

Known as allodynia, this nerve-pain condition makes normally harmless sensations, such as clothing brushing against the skin or a light touch, painful. Patients describe it as a sunburn without visible redness or irritation.

Although it is not an established side effect of Ozempic, Wegovy, Mounjaro or Zepbound, medical reports have documented similar symptoms. A direct link remains unproven.

"I have [areas] all over that are burning. It's driving me nuts," one Reddit user wrote. Another said painkillers and lidocaine gels offered little relief.

Some patients report improvement after reducing their dose or stopping treatment.

Also read: Ozempic Hair: GLP-1 Drug Use Linked To 7% Higher Baldness Risk In Men

Why Could Weight-Loss Injections Cause Burning Skin?

Semaglutide, used in Ozempic and Wegovy, mimics the GLP-1 hormone. Tirzepatide, used in Mounjaro and Zepbound, targets GLP-1 and GIP receptors.

Dr Richard Siegel, an endocrinologist at Tufts Medicine, told the Daily Mail that these drugs could potentially affect nerve signalling through the brain and spinal cord.

Another theory involves changes in the fat layer beneath the skin during weight loss, which could affect nerve sensitivity. Neither explanation has been proven.

What Do Medical Reports Reveal?

An October 2025 report documented two cases:

• A 56-year-old woman developed painful skin sensations after switching to semaglutide 2.4 mg. Symptoms resolved without treatment after six weeks.
• A 75-year-old man with type 2 diabetes developed widespread burning after switching to tirzepatide. Symptoms resolved after he discontinued it and returned to oral semaglutide.

Some patients report improvement over time or after reducing their dose.

Dr Siegel said symptoms can last days to weeks, potentially becoming less noticeable as the body adjusts to treatment, much like nausea and constipation.

"It's possible something similar is happening here, where temporary changes in receptor activity alter nerve signaling at first, but become less noticeable as the body adjusts," he said.

Read More: Stopping Ozempic, Wegovy, Mounjaro Linked To 22% Higher Heart Attack, Stroke Risk: Study

Newer Weight-Loss Drugs May Carry A Higher Risk

Clinical trials have also recorded dysesthesia, a broader category of abnormal sensations, including burning and tingling. It is not necessarily the same as allodynia.

In a high-dose oral semaglutide trial, dysesthesia occurred in fewer than 3% of 334 participants, compared with none receiving placebo.

Phase 3 trials of retatrutide, an experimental drug targeting GLP-1, GIP and glucagon receptors, reported:

• 9 mg dose: 8.8%
• 12 mg dose: 20.9%
• Placebo: 0.7%

Who Is More Vulnerable To Allodynia?

Risk factors remain unclear. Dr Siegel believes higher doses could play a role.

"As best as I can tell, it would mostly be people on higher doses of these medications," he said.

He also suggested that people with greater pain sensitivity, including those with fibromyalgia, might be more susceptible.

What Should Patients Do?

Patients experiencing unusual skin burning or sensitivity should consult their doctor. Dose adjustments or alternative treatments may be considered, but medication should not be changed or stopped without medical advice.

Allodynia can also occur with shingles, migraines and nerve damage, so symptoms should not automatically be attributed to weight-loss drugs.

Dr Siegel recommends recording when symptoms occur, where they appear and what makes them better or worse.

Persistent or worsening pain should be medically evaluated.

When was the last time you took the stairs without thinking twice, walked to the market without needing a break, or said yes to an outing without worrying about how tiring it might be?

Sometimes, the first sign that something has changed with your health is not a new symptom, but an activity you have quietly given up. A morning walk gets shorter, a flight of stairs calls for a pause, or a favourite weekend outing starts to feel like too much effort. It is easy to put these changes down to age, but they may be telling you something worth investigating.

A simple “activity audit” can help you connect the dots. Instead of asking only whether you feel unwell, compare what you could comfortably do a few years ago with what you can manage today.

Could you walk the same distance without stopping? Have stairs that once felt routine become difficult? Have you cut back on morning walks, stopped playing a favourite sport or become less inclined to leave the house? Do everyday activities such as grocery shopping, gardening or household chores require more effort than before?

These questions are particularly relevant after age 45, when declining stamina may be attributed entirely to ageing. However, a persistent change in exercise tolerance or everyday activity should not automatically be dismissed as a normal consequence of ageing.

Breathlessness during activity, unusual fatigue, dizziness or light-headedness, swelling in the feet or ankles, and palpitations can occur in people with heart valve disease. These symptoms can also have other causes, but if they are persistent, unexplained or worsening, they warrant discussion with a healthcare professional.

Heart valve disease can develop gradually, allowing people to adapt their routines without recognising the underlying problem. Someone who becomes breathless while walking may take shorter routes, while another person may avoid stairs or social activities that involve physical exertion. Eventually, these adjustments can become part of daily life, making it harder to recognise a change in health.

Looking back can help restore that perspective. A simple three-part comparison offers a useful starting point: What could I do before? What can I do now? What changed in between?

Family members can also help identify differences that an older relative may have overlooked. A parent who once travelled regularly may begin avoiding trips, while someone who enjoyed gardening, shopping or meeting friends may increasingly prefer to stay home. These observations cannot establish a diagnosis, but they can prompt a timely conversation about health.

If breathlessness, fatigue, dizziness, swelling, or palpitations are new, persistent, or interfering with everyday activities, consulting a doctor can help determine the cause. Depending on the symptoms and medical history, the evaluation may include a physical examination and an echocardiogram, commonly called a 2D echo. This ultrasound test helps assess the heart's structure and how its valves function.

An activity audit is not a diagnostic test. Its purpose is to help people recognise changes that might otherwise go unnoticed and decide when to seek medical advice.

Growing older does not necessarily mean giving up the activities that make everyday life enjoyable. Paying attention to changes in physical ability can help distinguish an expected adjustment from a potential health concern.

Start your activity audit today. Think about three activities you could comfortably do a few years ago but now find difficult, tiring or have stopped altogether. Note when these changes began and whether you have experienced symptoms such as breathlessness, unusual fatigue, dizziness or palpitations. If you notice a persistent or unexplained decline, schedule a consultation with your doctor and discuss whether further evaluation, including an echocardiogram, may be appropriate.

The question is simple: What have you stopped doing, and could your health be the reason? Taking that first step can help you understand the change and decide what to do next.

(By Dr. Sumanto Mukhopadhyay, a Senior Consultant Interventional and Structural Cardiologist, Apollo Hospital, Kolkata)

In a shocking viral trend, women in Kenya are reportedly inserting cetirizine, an allergy medication, into their vaginas in an attempt to achieve vaginal tightening and enhance sexual pleasure.

The practice has prompted warnings from pharmacists and health authorities, who caution that the drug is not meant for vaginal use and could pose health risks.

The Pharmaceutical Society of Kenya (PSK) has warned against the practice, stating that the medicine is not intended for vaginal use.

"Cetirizine is an allergy medicine, taken by mouth. It is not approved or tested for any other purpose, and definitely not for vaginal use," the PSK said in a statement issued on Thursday.

It advised women who had tried the practice to stop and seek medical attention if they experienced pain, bleeding, burning, itching, unusual discharge or fever.

What Is The Cetirizine Vaginal Tightening Trend?

Also read: Is Your Allergy Medicine Safe? FDA Recalls Antihistamine Tablets Over Life-Threatening Contamination Concerns

Posts circulating on Kenyan social media, particularly TikTok, claim that cetirizine can reduce vaginal moisture and create a sensation of tightness during sex, BBC reported.

The claims have sparked online debate, with some users endorsing the practice and others questioning its safety.

The trend has also reportedly increased demand for the drug, with local media reporting price rises and shortages at some pharmacies in Nairobi.

What Is Cetirizine And Why Is Its Misuse Dangerous?

Cetirizine is an oral antihistamine used to relieve allergy symptoms such as sneezing, runny nose, itchy eyes and hives.

Kenya's Pharmacy and Poisons Board (PPB) clarified in a public safety alert issued on November 4 that cetirizine is used to treat allergic rhinitis and urticaria. It is intended for oral use and should be taken only as directed by a healthcare professional.

The Board stressed that "the drug is not approved for vaginal use or tightening and that no established scientific evidence supports such claims".

On the other hand, inserting the tablets may cause vaginal irritation, burning, soreness, pain and discomfort. It may also disrupt the vagina's natural protective environment and increase infection risk.

The PSK cautioned against confusing dryness with tightening.

"Dryness is not tightness... instead, it may increase friction, discomfort, and the risk of tissue injury," it said.

Taking more than the recommended cetirizine dose can also cause excessive sleepiness, dizziness, restlessness, confusion, shaking, a rapid heartbeat and difficulty passing urine, the PPB warned.

Kenya's Health Ministry Raises Concern

Read More: California Reports 4 Cases Of Deadly Clade I Mpox virus: What To Know About Local Transmission Risk

Kenya's health ministry had also flagged the trend a day earlier. Ouma Oluga, a senior health official, expressed concern that social media users were dismissing medical warnings without considering the consequences, the BBC reported.

He suggested that authorities could introduce a system to monitor medicine distribution and purchases to identify potential misuse. No formal decision has been announced.

Pharmacists Warn Of Shortages And Misuse

The PSK said it had received reports of increased cetirizine demand, rising prices and shortages at some pharmacies.

It urged retailers not to exploit the trend, warning that people who need the drug for allergies could struggle to access it. Pharmacists were also advised against knowingly dispensing medicines for misuse.

The PPB urged women not to insert cetirizine or other oral medicines into the vagina and to consult healthcare professionals about vaginal dryness or sexual health concerns rather than follow unverified online advice.