These are tables of the clinically most important viruses. A vast number of viruses cause infectious diseases, but these are the major ones]citation needed[.
A local anesthetic (LA) is a drug that causes reversible local anesthesia, generally for the aim of having a local analgesic effect, that is, inducing absence of pain sensation, although other local senses are often affected as well. Also, when it is used on specific nerve pathways (nerve block), paralysis (loss of muscle power) can be achieved as well.
Clinical local anesthetics belong to one of two classes: aminoamide and aminoester local anesthetics. Synthetic local anesthetics are structurally related to cocaine. They differ from cocaine mainly in that they have no abuse potential and do not act on the sympathoadrenergic system, i.e. they do not produce hypertension or local vasoconstriction, with the exception of Ropivacaine and Mepivacaine that do produce weak vasoconstriction.
Sexually transmitted diseases (STD), also referred to as sexually transmitted infections (STI) and venereal diseases (VD), are illnesses that have a significant probability of transmission between humans by means of sexual behavior, including vaginal intercourse, anal sex and oral sex. Some STIs can also be contracted by using IV drug needles after their use by an infected person, as well as through childbirth or breastfeeding.
Sexually transmitted infections have been well known for hundreds of years, and venereology is the branch of medicine that studies these diseases. While in the past, these illnesses have mostly been referred to as STDs or VD, in recent years the term sexually transmitted infections (STIs) has been preferred, as it has a broader range of meaning; a person may be infected, and may potentially infect others, without having a disease.
Herpes zoster (or simply zoster), commonly known as shingles and also known as zona, is a viral disease characterized by a painful skin rash with blisters in a limited area on one side of the body (left or right), often in a stripe. The initial infection with varicella zoster virus (VZV) causes the acute, short-lived illness chickenpox which generally occurs in children and young adults. Once an episode of chickenpox has resolved, the virus is not eliminated from the body and can go on to cause shingles—an illness with very different symptoms—often many years after the initial infection. Herpes zoster is not the same disease as herpes simplex, despite the name similarity; both the varicella zoster virus and herpes simplex virus belong to the same viral subfamily Alphaherpesvirinae.
After the initial episode of chickenpox resolves, the varicella zoster virus remains latent in the nerve cell bodies and, less frequently, the non-neuronal satellite cells of the dorsal root, cranial nerve or autonomic ganglia, without causing any symptoms. Years or decades after the initial infection, the virus may break out of nerve cell bodies and travel down nerve axons to cause viral infection of the skin in the region of the nerve. The virus may spread from one or more ganglia along nerves of an affected segment and infect the corresponding dermatome (an area of skin supplied by one spinal nerve) causing a painful rash. Although the rash usually heals within two to four weeks, some sufferers experience residual nerve pain for months or years, a condition called postherpetic neuralgia. Exactly how the virus remains latent in the body, and subsequently re-activates, is not understood.
Herpes simplex (Greek: ἕρπης herpēs, "creeping" or "latent") is a viral disease from the herpesviridae family caused by both Herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2). Infection with the herpes virus is categorized into one of several distinct disorders based on the site of infection. Oral herpes, the visible symptoms of which are colloquially called cold sores or fever blisters, is an infection of the face or mouth. Oral herpes is the most common form of infection. Genital herpes, known simply as herpes, is the second most common form of herpes. Other disorders such as herpetic whitlow, herpes gladiatorum, ocular herpes, cerebral herpes infection encephalitis, Mollaret's meningitis, neonatal herpes, and possibly Bell's palsy are all caused by herpes simplex viruses.
Herpes viruses cycle between periods of active disease—presenting as blisters containing infectious virus particles—that last 2–21 days, followed by a remission period. Genital herpes, however, is often asymptomatic, though viral shedding may still occur. After initial infection, the viruses are transported along sensory nerves to the sensory nerve cell bodies, where they become latent and reside lifelong. Causes of recurrence are uncertain, though some potential triggers have been identified, including immunosuppressant drugs. The previously latent virus then multiplies new virus particles in the nerve cell and these are transported along the axon of each neuron to the nerve terminals in the skin, where they are released. Over time, episodes of active disease reduce in frequency and severity.
Postherpetic neuralgia is a nerve pain due to damage caused by the varicella zoster virus. Typically, the neuralgia is confined to a dermatomic area of the skin and follows an outbreak of herpes zoster (commonly known as shingles) in that same dermatomic area. The neuralgia typically begins when the herpes zoster vesicles have crusted over and begun to heal, but it can begin in the absence of herpes zoster, in which case zoster sine herpete is presumed (see Herpes zoster).
Treatment options for postherpetic neuralgia include antidepressants, anticonvulsants (such as gabapentin, pregabalin, or topiramate) and topical agents such as lidocaine patches or capsaicin lotion. Opioid analgesics may also be appropriate in many situations. There are some sporadically successful experimental treatments, such as rhizotomy (severing or damaging the affected nerve to relieve pain) and TENS (a type of electrical pulse therapy).