What Are the Most Common Causes of a Rash with Blisters?

Herpes is a disease caused by a herpesviridae virus. Eight types of viruses (herpes simplex virus type 1 and type 2, varicella-zoster virus, human cytomegalovirus, EB virus, and human herpes virus types 6, 7, and 8) in the herpesviridae family are currently known to cause human disease This type of virus is collectively referred to as the human herpes virus (HHV). HHV is a group of medium-sized encapsulated DNA viruses that can cause a variety of human diseases, and can be dormant in the body for a long time, and recurrence of infection under certain conditions. Clinically common diseases such as chicken pox, shingles, herpes simplex, and genital herpes. It can invade many organs of the human body and can be affected at any age.

Basic Information

English name

herpes

Visiting department

dermatology

Common causes

Caused by herpes virus

Common symptoms

Different manifestations, obvious pain in herpes zoster patients

Causes of herpes

The herpes virus has the following common characteristics: The virus is spherical. The surface of the viral nucleocapsid is a symmetrical icosahedron composed of 162 shell particles, and the core is composed of DNA. There is a layer of lipoprotein envelope around the nucleocapsid, and the outer diameter of the virus is 150-200nm. Except for Epstein-Barr virus, they can replicate in the nucleus of diploid cells, and eosinophilic inclusion bodies appear in the nucleus. The virus can spread directly through the intercellular bridge. Herpes virus mainly invades ectoderm-derived tissues, including skin, mucosa, and nerve tissue. Herpes virus has three subfamilies of , , and . Those related to human infection include the following:

1.HHV-1

Herpes simplex virus type 1 (HSV-1) belongs to alpha herpes virus. The primary infection of HSV-1 mostly occurs in infants and young children after half a year old, and most of them are recessive. The virus is latent in the trigeminal ganglia and superior cervical ganglia. A small number of patients may present with acute herpes stomatitis, herpes keratoconjunctivitis, herpes eczema, and herpes encephalitis. Herpes encephalitis occurs in older children and adults, with a mortality rate of 70%.

2.HHV-2

Herpes simplex virus type 2 (HSV-2) belongs to alpha herpes virus. The primary infection of HSV-2 is more common in patients after puberty, and can be latent in the sacral ganglia, mainly causing genital herpes.

3.HHV-3

Varicella-zoster virus (VZV), an alpha-herpes virus, causes chickenpox and shingles. Chickenpox is a multiple infectious disease in children, and shingles is a sporadic disease in adults.

4.HHV-4

Human herpesvirus type 4 (EBV), which belongs to the gamma herpes virus, is a lymphocytic virus that causes human infectious mononucleosis and is also associated with the pathogenesis of Birch lymphoma and nasopharyngeal carcinoma.

5.HHV-5

Cytomegalovirus (CMV), a beta herpes virus. Can cause congenital infections, and those infected during pregnancy can be transmitted to the fetus through the placenta. In addition, CMV may have a carcinogenic effect.

6.HHV-6

Roseolavirus is a beta herpes virus. Will cause the sixth disease, which is acute rash in children (baby rose rash). Like other herpes viruses, a primary infection can cause a latent infection.

7.HHV-7

It is similar to HHV-6 and belongs to beta herpes virus. Caused by the same symptoms.

8.HHV-8

It is a genus of monkey virus (kSHV), which belongs to gamma herpes virus. It can be found in lymphoid tissues of patients with Kaposi's sarcoma and AIDS.

Clinical manifestations of herpes

1. Varicella-zoster virus-induced diseases

(1) Shingles is an acute infectious skin disease caused by varicella-zoster virus. Some patients become infected with the virus without symptoms. Because the virus is neurotropic, it can lurk in the neurons of the spinal nerve's posterior root ganglia for a long time after infection. When the resistance is low or tired, infected, and cold, the virus can grow and reproduce again and move along the nerve fibers to the skin. Causes intense inflammation of affected nerves and skin. The rash is generally unilateral and distributed by nerve segments. The predominant sites are the intercostal nerve, cervical nerve, trigeminal nerve, and lumbosacral innervation zone, which are clustered with herpes and associated with pain. Age The larger it is, the more severe the neuralgia and can cause postherpetic neuralgia. The disease is common in adults and is more common in spring and autumn. Incidence increased significantly with age.

(2) Varicella-herpes uveitis can be congenital or acquired. The acute retinal necrosis syndrome caused by it has become an important blinding eye disease. Varicella-zoster virus isolation and culture from infected tissues can confirm the diagnosis. Slit lamp examination can detect anterior uveopathy; fundus fluorescein angiography can detect retinal vasculitis and corresponding characteristic changes of retinal neovascular discitis.

(3) The typical lesions of herpes zoster are mostly in the skin distribution areas of the first branch of the trigeminal nerve (frontal nerve, lacrimal nerve, and nasal ciliary nerve) or the third main branch (rarely). Cluster vesicular rash. It does not cross the central boundary of the eyelid and nose, but is limited to one side. More common in middle-aged and elderly patients. Rarely recurs after healing.

(4) Ear shingles was first described by RamseyHunt in 1907, so it is also called RamseyHunt syndrome or Hunt syndrome, or Hunt syndrome, which is a disease infected by chickenpox-zoster virus. A group of special symptoms caused by facial nerve and geniculate ganglion herpes virus infection, which are mainly manifested as severe pain in one ear and herpes in the ear. Peripheral facial paralysis with ipsilateral hearing and balance disorders may occur, so it is also called knee Ganglia syndrome.

2. Diseases caused by herpes simplex virus

(1) Neonatal herpes simplex is more common in premature infants and can also occur in term infants. Lesions often involve multiple organs throughout the body. 70% is caused by HSV-2. It usually occurs 3 to 5 days after birth and manifests as blisters and erosions on the skin, oral mucosa, and conjunctiva. Severe cases may be accompanied by fever, dyspnea, jaundice, hepatosplenomegaly, consciousness. Obstacles, etc.

(2) Pregnant women with genital herpes often have recurrent vulvar herpes before pregnancy. They are infected with herpes simplex virus and dormant in the body. They are induced by pregnancy virus reactivation. Common vulva has 2 to 3 ulcers or blisters, the course of disease is short, and healed naturally in about a week. If a pregnant woman is infected with herpes virus for the first time in the first trimester (within the first trimester of pregnancy) and has obvious symptoms, she may be prone to miscarriage or stillbirth. If a pregnant woman is infected with herpes virus for the first time in the third trimester (the last trimester of pregnancy), the virus can spread to the fetus, making the newborn susceptible to neonatal herpes and possibly causing neonatal death.

(3) Genital herpes, also known as genital herpes, is a sexually transmitted disease caused by herpes simplex virus (HSV), mainly HSV-2, and a few are HSV-1. It is one of the common sexually transmitted diseases. The disease is mainly transmitted through sexual contact. Patients and asymptomatic carriers are the main source of infection. Genital herpes can recur, which has a greater impact on the patient's health and psychology; it can also infect newborns through the placenta and birth canal, causing congenital infections in newborns. The affected part had a burning sensation first, and then erythema appeared; 3 to 10 clusters of red pimples soon developed on the basis of erythema, accompanied by pruritus; the pimples quickly turned into small blisters, which turned into pustules after 3 to 5 days, broken After the ulceration, erosions and ulcers are formed, the pain is conscious, and finally the scabs heal. the illness might last 20 days or so. Recurrent genital herpes occurs within 1 to 4 months after the onset. Recurrence mostly occurs in the vulva, vagina, cervix, and glans, and the systemic symptoms are lighter than the primary, and the duration of each attack is shorter. Usually, the skin lesions subsid about 10 days.

(4) Herpes gingivostomatitis occurs in the mouth, gums, tongue, hard palate, pharynx and other parts. It appears as a cluster of small blisters that occur quickly, and quickly ulcerate to form a surface ulcer. It can also begin to appear as erythema and superficial ulcers with obvious pain. The natural course is 1 to 2 weeks. It can be repeated in the same part under the stimulation of evoking factors, which is called relapse, and it is more common in adults.

(5) Herpes simplex encephalitis is the most common viral infectious disease of the central nervous system caused by herpes simplex virus infection. It often affects the temporal lobe, frontal lobe and limbic system of the brain, causing hemorrhagic necrosis of brain tissue and allergic brain damage.

(6) Inoculated herpes Skin lesions are clustered blister confined to the contact area. Occurred in the fingers are deep painful blisters, called herpes gangrene.

(7) Herpes eczema often occurs in infants and young children with eczema or specific dermatitis, mostly caused by HSV-1, manifested as dense blisters or pustules that occur in the upper trunk, neck and head, fused into a slice There is an umbilical depression in the center of the blister, and there is a red halo around it.

Herpes test

Varicella-zoster virus

(1) Detection of antigen The antigen in herpes basal cell scrapes or herpes fluid can be checked by direct immunofluorescence, enzyme immunostaining, or ELISA methods, and diagnosis can be made directly.

(2) Detection of IgM antibodies by ELISA method The incubation period of chickenpox is usually about 2 weeks. When a rash occurs, IgM antibodies in the blood have been produced. IgM antibodies can be maintained for about 2 months, and detection of IgM antibodies can help establish a diagnosis. This method has strong specificity and high sensitivity. Herpes zoster is a recurrent infection with low IgM antibody titer and short time, and 70% can be detected by radioimmunoassay.

Herpes simplex virus

(1) Immunofluorescence or enzyme staining for antigen detection It is used for cell smears such as cervical exfoliated cells, corneal scraping cells, and ulcer bottom scraping cells. Direct immunofluorescence or enzyme immunostaining is used for antigen detection. Positive results indicate infection.

(2) Double-antibody sandwich ELISA for detecting antigens It is mainly used to detect HSV antigens in cerebrospinal fluid. It can also be used to detect HSV antigens in patients with herpes sores, scrapes at the bottom of ulcers, and biopsies.

Herpes diagnosis

It is not difficult to make a diagnosis based on medical history, typical clinical manifestations, and laboratory test results.

Herpes treatment

General treatment

Pay attention to rest, eat easily digestible food, and pay attention to hydration. Strengthen care to keep skin clean and prevent secondary bacterial infections. Clothes, bedding, towels, dressings, etc. that come in contact with herpes fluids should be disinfected in a timely manner and not shared with healthy people. Herpes gingivostomatitis should keep the mouth clean and rinse with a 1: 1000 benzalkonium bromide solution. Avoid sexual life during genital herpes treatment.

Symptomatic treatment

Those who do not have itchy skin can be rubbed with calamine lotion, and antibiotic ointment can be applied after herpes rupture. People with obvious herpes zoster pain should be given analgesics such as indomethacin, etc. At the same time, vitamin B ₁ and B ₁₂ can be given orally or intramuscularly. For secondary infection, use 0.5% neomycin cream or mupirocin ointment for external application.

3. Antiviral therapy

Nucleosides are currently considered to be the most effective anti-HSV drugs. Acyclovir, valacyclovir or famciclovir can be taken orally. Topical lesions can be treated with acyclovir ointment or penciclovir cream.