HEALTH AND MEDICAL PRODUCTS:COLD SORETREA TMENTS.

COLD SORETREA TMENTS

Herpes labialis (cold sore or fever blister) is a painful and highly contagious infection caused by the herpes simplex type 1 virus (HSV1). The herpesviruses are a large group of double-stranded DNA viruses that cause a variety of diseases in humans and animals. One of the interesting features of some herpesviruses is their ability to remain latent (“lying dormant”) in the body for long periods of time after the primary infection, becoming reactivated under conditions such as exposure to heat or cold, hormonal or emotional disturbances, gastrointestinal disturbance, certain foods, stress, fever, infection, common cold, allergies, sunburn (ultraviolet light exposure), female menstruation, pregnancy, or by other unknown stimuli. Latent herpes infections are apparently quite common, with the virus persisting in low numbers within the nervous system via ascending sensory nerve fibers, emerging within epithelial cells in the skin or mucus membranes possibly years later at or near the original site of Aviral entry. Thus, while the immune system of a healthy individual responds to an initial attack by HSV1 and resolves the symptoms, the virus is able to maintain a small colony of live viruses within the individual, thereby posing a risk of viral reactivation and subsequent additional cold sore formation.

An HSV1 infection (whether primary or reactivated) is usually charac- terized by the formation of a small group of superficial blistering vesicles (cold sores, fever blisters) appearing on the gums, outside of the mouth and lips, nose (nostrils), cheeks, or fingers (blister stage). The vesicles (blisters) first form and then break open and ooze fluid (weeping stage), leaving a painful reddish ulceration whose surface soon takes on a gray appearance. An exterior yellow crust then develops and eventually sloughs off (crusting stage), revealing new skin underneath (final healing stage). Although the incubation period of HSV1 infection is short (three to five days), untreated cold sores usually remain for approximately seven to ten days, often requiring up to twenty-one days for complete skin healing. Although cold sores generally are not considered seriously dangerous, the infection may be life threatening for individuals whose immune sys- tem is depressed by disease or medications. HSV1 may be contracted by children over six months old and may lead to serious illness. In addition, a cold sore infection may cause blindness in both adults and children if the virus spreads to the eye area, and it may lead to the formation of genital lesions if the infection is spread directly or indirectly to the genitals.

Viruses (from the Latin virus, referring to poison) are nonliving obli- gate intracellular parasites composed of protein and nucleic acid (DNA or RNA) that manipulate the host cell to produce and manufacture more viruses. Viral infection occurs by the attachment of virus particles to spe- cific cell receptors within the host cell. After fusion of the host cell plasma membrane with the virus outer envelope, the protein-based viral nucleocapsid (containing the viral DNA) is transported to the host cell nucleus, where components of the viral particle inhibit macromolecular synthesis by the host cell. Herpes viral DNA and new viral nucleocapsid synthesis occurs within the host nucleus, with the acquisition of new viral envelopes via a budding process through the inner membrane of the host nucleus. The mature newly synthesized viral particles are subsequently released through an intracellular membranous organelle system to the outside of the cell and are capable of infecting other host cells.

On initial contact with HSV1, it is estimated that more than 90 per- cent of humans develop primary herpes. After the primary infection, most humans usually develop specific antibodies. However, despite the presence of these protective antibodies, many adults have repeated cold sore infections. Sores may develop as late as twenty days after the initial exposure to the virus. Herpes viruses are considered extremely contagious. In ancient Rome, an epidemic of cold sores prompted Emperor Tiberius to ban kissing in public ceremonies. It is estimated that more than 100 million episodes of recurrent cold sore outbreaks occur annually within the United States alone.

Viral contact may occur directly through skin-to-skin interaction with cold sores or other herpes lesions (e.g., kissing, hand touching) or through contact with infected razor blades, towels, dishes, utensils, toothbrushes, and so on. Suggestions for the prevention of viral infection include avoiding direct contact with cold sores or herpes lesions in general, washing items that come in contact with the cold sore lesion in hot (preferably boiling) water before reuse, washing hands carefully before touching another person after having touched a cold sore, and avoiding precipitating causes if prone to oral herpes outbreaks.

Symptoms of aches, fatigue, and lack of energy frequently accompany cold sore outbreaks, with fever or flulike symptoms and swollen lymph nodes in the neck often accompanying the first HSV1 attack. Signs and symptoms of cold sores include small, fluid-filled blisters on a raised, red, painful area of the skin near the mouth, or on the fingers, with swollen, sensitive gums of a deep red color. Frequently, pain, itching, sensitivity, or a tingling sensation (tingle stage) at the site (called the prodome) pre- cedes the blistering by one to two days. Diagnosis by a medical professional is made on the basis of the appearance and/or viral culture of the lesion, with additional examination possibly showing enlargement of the neck lymph nodes.

While for most adults and children, cold sores generally clear up with- out treatment in seven to ten days, pain may be alleviated by home remedies such as avoiding spicy or acidic foods, applying ice or warmth to the blisters, or applying a moistened tea bag to the area, as it has been suggested that tannic acid (a chemical found in tea) may possess antiviral properties. Unfortunately, the HSV1 infection itself cannot be “cured.” It is recommended that patients wash blisters gently with soap and water and dry thoroughly to prevent secondary bacterial infections.

Over-the-counter topically applied medical treatments often contain anesthetic-like numbing agents that temporarily inactivate nerve endings in the skin, such as phenol (C6H6O), camphor, benzyl alcohol (C7H8O), lidocaine, benzocaine, or tetracaine, that assist in drying and alleviating burning, itching, and pain. Medications (e.g., lip balms) that moisturize and soften cold sores to reduce cracking and bleeding include emollients such as petroleum jelly, allantoin, light mineral oil, cetyl alcohol, cocoa butter, glycine, modified lanolin, aloe vera gel, jojoba oil, peppermint oil, meadowfoam seed oil, eucalyptus oil, and beeswax. Anti-itch ingredi- ents (e.g., menthol) can also be included, along with skin-soothing vita- mins (e.g., a.-tocopherol, tetrahexyldecyl ascorbate) and herbal extracts (e.g., echinacea, green tea extract, grape seed extract). Since excessive ex- posure to ultraviolet light may lead to cold sore formation, many lip balm medications also contain agents that act as sunscreens (e.g., zinc oxide, which also acts as an antimicrobial agent). In addition, metals such as zinc and amino acids such as lysine have been suggested to exhibit antiviral properties; thus, they are thought to have an inhibitory effect on the ability of the herpesvirus particles to form cold sore lesions.

Over-the-counter topically applied virus-inhibiting medications for cold sores may include products containing docosanol (C22H46O) (also called behenyl alcohol, behenic alcohol, 1-docosanol, docosyl alcohol, or n- docosanol), an antiviral chemical used to treat symptoms (e.g., pain, dis- comfort) of lipid-enveloped viral infections (including HSV1). Docosanol inhibits fusion between the plasma membrane and the HSV1 envelope, thereby preventing viral entry into cells and subsequent viral replication. Thus, docosanol may lead to a significant reduction in the duration of symp- toms associated with HSV1 infection, including pain, burning, itching, and tingling.