Cold Sores

Cold sores also called fever blisters — are a common viral infection. They are tiny, fluid-filled blisters on and around your lips. These blisters are often grouped together in patches. After the blisters break, a crust forms over the resulting sore. Cold sores usually heal in two to four weeks without leaving a scar.

Cold sores spread from person to person by close contact, such as kissing. They're caused by a herpes simplex virus (HSV-1) closely related to the one that causes genital herpes (HSV-2). Both of these viruses can affect your mouth or genitals and can be spread by oral sex. Cold sores are contagious even if you don't see the sores.

There's no cure for HSV infection, and the blisters may return. Antiviral medications can help cold sores heal more quickly and may reduce how often they return.

Symptoms

A cold sore usually passes through several stages:

· Tingling and itching.Many people feel an itching, burning or tingling sensation around their lips for a day or so before a small, hard, painful spot appears and blisters erupt.
· Blisters. Small fluid-filled blisters typically break out along the border where the outside edge of the lips meets the skin of the face. Cold sores can also occur around the nose or on the cheeks.
· Oozing and crusting. The small blisters may merge and then burst, leaving shallow open sores that will ooze fluid and then crust over.

Signs and symptoms vary, depending on whether this is your first outbreak or a recurrence. They can last several days, and the blisters can take two to four weeks to heal completely. Recurrences typically appear at the same spot each time and tend to be less severe than the first outbreak.

During first-time outbreaks, some people also experience: Fever, painful eroded gums, sore throat, headache, muscle aches, swollen lymph nodes

Children under 5 years old may have cold sores inside their mouths and the lesions are commonly mistaken for canker sores. Canker sores involve only the mucous membrane and aren't caused by the herpes simplex virus.

Causes

Cold sores are caused by certain strains of the herpes simplex virus (HSV). HSV-1 usually causes cold sores. HSV-2 is usually responsible for genital herpes. However, either type can cause sores in the facial area or on the genitals. Most people who are infected with the virus that causes cold sores never develop signs and symptoms.

Cold sores are most contagious when oozing blisters are present. But you can transmit the virus to others even if you don't have blisters. Shared eating utensils, razors and towels, as well as kissing, may spread HSV-1. Oral sex can spread HSV-1 to the genitals and HSV-2 to the lips.

Once you've had an episode of herpes infection, the virus lies dormant in nerve cells in your skin and may emerge as another cold sore at the same place as before. Recurrence may be triggered by:

· Viral infection or fever
· Hormonal changes, such as those related to menstruation
· Stress
· Fatigue
· Exposure to sunlight and wind
· Changes in the immune system

Risk factors

About 90 percent of adults worldwide — even those who've never had symptoms of an infection — test positive for evidence of the virus that causes cold sores.

People who have weakened immune systems are at higher risk of complications from the virus. Medical conditions and treatments that increase your risk of complications include:

· HIV/AIDS
· Severe burns
· Eczema
· Cancer chemotherapy
· Anti-rejection drugs for organ transplants

Complications

In some people, the virus that causes cold sores can cause problems in other areas of the body, including:

· Fingertips. Both HSV-1 and HSV-2 can be spread to the fingers. This type of infection is often referred to as herpes whitlow. Children who suck their thumbs may transfer the infection from their mouths to their thumbs.
· Eyes. The virus can sometimes cause eye infection. Repeated infections can cause scarring and injury, which may lead to vision problems or blindness.
· Widespread areas of skin. People who have a skin condition called eczema are at higher risk of cold sores spreading all across their bodies. This can become a medical emergency.
· Other organs. In people with weakened immune systems, the virus can also affect organs such as the spinal cord and brain.

Tests and diagnosis

Your doctor can usually diagnose cold sores just by looking at them. To confirm the diagnosis, he or she may take a sample from the blister for testing in a laboratory.

Treatments and drugs

Several types of prescription antiviral drugs may speed the healing process. Examples include:

• Acyclovir
• Valacyclovir
• Famciclovir
• Penciclovir

Some of these products are packaged as pills to be swallowed. Others are creams to be applied to the sores several times a day.

Prevention

Your doctor may prescribe an antiviral medication for you to take on a regular basis, if you develop cold sores frequently or if you're at high risk of serious complications. If sunlight seems to trigger your recurrences, apply sunblock to the spot where the cold sore tends to erupt.

To help avoid spreading cold sores to other people or to other parts of your body, you might try some of the following precautions:

· Avoid skin-to-skin contact with others while blisters are present. The virus spreads most easily when there are moist secretions from the blisters.
· Avoid sharing items. Utensils, towels, lip balm and other items can spread the virus when blisters are present.
· Keep your hands clean. When you have a cold sore, wash your hands carefully before touching yourself and other people, especially babies.

Reference: Mayo Clinic

Chickenpox (Varicella)

Chickenpox is an acute, systemic, usually childhood infection caused by the varicella-zoster virus (human herpesvirus type 3). It usually begins with mild constitutional symptoms that are followed shortly by skin lesions appearing in crops and characterized by macules, papules, vesicles, and crusting. Patients at risk of severe neurologic or other systemic complications (eg, pneumonia) include adults, neonates, and patients who are immunocompromised or have certain underlying medical conditions. Diagnosis is clinical. Those at risk of severe complications receive postexposure prophylaxis with immune globulin and, if disease develops, are treated with antiviral drugs (eg, valacyclovir, famciclovir, acyclovir). Vaccination provides effective prevention in immunocompetent patients.

Chickenpox is caused by the varicella-zoster virus (human herpesvirus type 3); chickenpox is the acute invasive phase of the infection, and herpes zoster (shingles) represents reactivation of the latent phase.

Chickenpox, which is extremely contagious, is spread by

· Mucosal (usually nasopharyngeal) inoculation via infected airborne droplets or aerosolized particles
· Direct contact with the virus (eg, via skin lesions)

Chickenpox is most communicable during the prodrome and early stages of the eruption. It is communicable from 48 h before the first skin lesions appear until the final lesions have crusted. Indirect transmission (by carriers who are immune) does not occur.

Epidemics occur in winter and early spring in 3- to 4-yr cycles. Some infants may have partial immunity, probably acquired transplacentally, until age 6 mo.

Symptoms and Signs

In immunocompetent children, chickenpox is rarely severe. In adults and immunocompromised children, infection can be serious.

Mild headache, moderate fever, and malaise may occur 10 to 21 days after exposure, about 24 to 36 h before lesions appear. This prodrome is more likely in patients > 10 yr and is usually more severe in adults.

Initial rash

The initial rash, a macular eruption, may be accompanied by an evanescent flush. Within a few hours, lesions progress to papules and then characteristic, sometimes pathognomonic teardrop vesicles, often intensely itchy, on red bases. The lesions become pustular and then crust.

Chickenpox (Face)

Lesions initially develop on the face and trunk and erupt in successive crops; some macules appear just as earlier crops begin to crust. The eruption may be generalized (in severe cases) or more limited but almost always involves the upper trunk.

Ulcerated lesions may develop on the mucous membranes, including the oropharynx and upper respiratory tract, palpebral conjunctiva, and rectal and vaginal mucosa.

In the mouth, vesicles rupture immediately, are indistinguishable from those of herpetic gingivostomatitis, and often cause pain during swallowing.

Scalp lesions may result in tender, enlarged suboccipital and posterior cervical lymph nodes.

New lesions usually cease to appear by the 5th day, and the majority are crusted by the 6th day; most crusts disappear <20 days after onset.

Breakthrough varicella

Sometimes vaccinated children develop varicella (called breakthrough varicella); in these cases, the rash is typically milder, fever is less common, and the illness is shorter; the lesions are infectious.

Complications

Secondary bacterial infection (typically streptococcal or staphylococcal) of the vesicles may occur, causing cellulitis or rarely necrotizing fasciitis or streptococcal toxic shock.

Pneumonia may complicate severe chickenpox in adults, neonates, and immunocompromised patients of all ages but usually not in immunocompetent young children.

Myocarditis, hepatitis, and hemorrhagic complications may also occur.

Acute postinfectious cerebellar ataxia is one of the most common neurologic complications; it occurs in 1/4000 cases in children.

Transverse myelitis may also occur.

Reye syndrome, a rare but severe childhood complication, may begin 3 to 8 days after onset of the rash; aspirin increases the risk.

In adults, encephalitis, which can be life threatening, occurs in 1 to 2/1000 cases of chickenpox.

Diagnosis

Clinical evaluation: Chickenpox is suspected in patients with the characteristic rash, which is usually the basis for diagnosis. The rash may be confused with that of other viral skin infections. If the diagnosis is in doubt, laboratory confirmation can be done. Samples are generally obtained with scraping and transported to the laboratory in viral media.

Prognosis

Chickenpox in children is rarely severe. Severe or fatal disease is more likely in the following: Adults, Patients with depressed T-cell immunity (eg, lymphoreticular cancer), those receiving corticosteroids or chemotherapy

Treatment

Symptomatic treatment in children is required. Relief of itching and prevention of scratching, which predisposes to secondary bacterial infection, may be difficult. Wet compresses or, for severe itching, systemic antihistamines and colloidal oatmeal baths may help. Simultaneous use of large doses of systemic and topical antihistamines can cause encephalopathy and should be avoided.

To prevent secondary bacterial infection, patients should bathe regularly and keep their underclothing and hands clean and their nails clipped. Antiseptics should not be applied unless lesions become infected; bacterial superinfection is treated with antibiotics.

Oral antivirals,when given to immunocompetent patients within 24 h of the rash’s onset, slightly decrease symptom duration and severity. However, because the disease is generally benign in children, antiviral treatment is not routinely recommended.

Oral acyclovir, valacyclovir, famciclovir should be given to healthy people at risk of moderate to severe disease, including all patients ≥ 12 yr and those with skin disorders (particularly eczema) or chronic lung disease.

Patients should not return to school or work until the final lesions have crusted.

Prevention

Infection provides lifelong protection.

Potentially susceptible people should take strict precautions to avoid people capable of transmitting the infection.

Herpes Zoster(Shingles; Acute Posterior Ganglionitis)

Herpes zoster is infection that results when varicella-zoster virus reactivates from its latent state in a posterior dorsal root ganglion. Symptoms usually begin with pain along the affected dermatome, followed in 2 to 3 days by a vesicular eruption that is usually diagnostic. Treatment is antiviral drugs and possibly corticosteroids given within 72 h after skin lesions appear.

Chickenpox and herpes zoster are caused by the varicella-zoster virus (human herpesvirus type 3); chickenpox is the acute invasive phase of the virüs and herpes zoster (shingles) represents reactivation of the latent phase. Herpes zoster inflames the sensory root ganglia, the skin of the associated dermatome, and sometimes the posterior and anterior horns of the gray matter, meninges, and dorsal and ventral roots. Herpes zoster frequently occurs in elderly and HIV-infected patients and is more severe in immunocompromised patients. There are no clear-cut precipitants.

Symptoms and Signs

Lancinating, dysesthetic, or other pain develops in the involved site, followed in 2 to 3 days by a rash, usually crops of vesicles on an erythematous base. The site is usually one or more adjacent dermatomes in the thoracic or lumbar region. Lesions are typically unilateral. The site is usually hyperesthetic, and pain may be severe. Lesions usually continue to form for about 3 to 5 days. Herpes zoster may disseminate to other regions of the skin and to visceral organs, especially in immunocompromised patients.

Fewer than 4% of patients with herpes zoster experience another outbreak. However, many, particularly the elderly, have persistent or recurrent pain in the involved distribution (postherpetic neuralgia), which may persist for months, years, or permanently. Infection in the trigeminal nerve is particularly likely to lead to severe, persistent pain. The pain of postherpetic neuralgia may be sharp and intermittent or constant and may be debilitating.

Geniculate zoster (Ramsay Hunt syndrome) results from involvement of the geniculate ganglion. Ear pain, facial paralysis, and sometimes vertigo occur. Vesicles erupt in the external auditory canal, and taste may be lost in the anterior two thirds of the tongue

Ophthalmic herpes zoster results from involvement of the gasserian ganglion, with pain and vesicular eruption in and around the eye, in the distribution of the ophthalmic division of the 5th cranial nerve. Vesicles on the tip of the nose (Hutchinson's sign) indicate involvement of the nasociliary branch and often severe ocular disease. However, eye involvement may occur in the absence of lesions on the tip of the nose.

Intraoral zoster is uncommon but may produce a sharp unilateral distribution of lesions. No intraoral prodromal symptoms occur.

Diagnosis

Clinical evaluation

Herpes zoster is suspected in patients with the characteristic rash and sometimes in patients with typical pain in a dermatomal distribution. Diagnosis is usually based on the virtually pathognomonic rash. If the diagnosis is equivocal, detecting multinucleate giant cells with a Tzanck test can confirm infection, but the Tzanck test is positive with herpes zoster or herpes simplex. Herpes simplex virus (HSV) may cause nearly identical lesions, but unlike herpes zoster, HSV tends to recur and is not dermatomal. Viruses can be differentiated by culture. Antigen detection from a biopsy sample can be useful.

Treatment

Symptomatic treatment

Antivirals ( acyclovir, famciclovir, valaciclovir) for immunocompromised or pregnant patients

compresses are soothing, but systemic analgesics are often necessary. Treatment with oral antivirals decreases the severity and duration of the acute eruption, the incidence of postherpetic neuralgia, and the rate of serious complications in immunocompromised patients and pregnant women. Treatment should start as soon as possible, ideally during the prodrome, and is likely to be ineffective if given > 72 h after skin lesions appear.

Prevention

Prevention involves preventing primary infection (chickenpox) by using the varicella vaccine in children and susceptible adults. Adults ≥ 60 yr should have a single dose of zoster vaccine (a more potent preparation of varicella vaccine) whether they have had herpes zoster or not. This vaccine has been shown to decrease the incidence of zoster.

Reference: The Merck Manual.