What Is Prurigo Simplex?

The disease is caused by human herpes simplex virus (HSV), which often invades the junction of the skin and mucous membranes. The rash is a localized cluster of small vesicles. The long-term incubation and recurrence of the virus are its clinical features.

Basic Information

English name

herpes simplex, HS

Visiting department

dermatology

Common locations

skin

Common causes

Caused by herpes simplex virus

Common symptoms

First infection is often accompanied by systemic symptoms, and skin lesions need to heal in 2 to 3 weeks

Causes of herpes simplex

Human HSV DNA-like viruses are divided into two subtypes according to their antigenic properties: HSV- and HSV-. HSV- mainly invades the face, brain, and upper waist, and HSV- mainly invades the genitals and lower waist. Normal people can be carriers of the virus. Humans are the only natural host for herpes simplex virus, and 70% to 90% of adults have been infected with HSV-. The virus invades the body through the mouth, respiratory tract, genitals, and damaged skin, and resides in the normal mucosa, blood, saliva, nerve tissue and most organs of the human body. When certain predisposing factors such as fever, cold, sun, emotional excitement, gastrointestinal dysfunction, drug allergy, excessive fatigue, mechanical stimulation, and menstruation, pregnancy, etc. all contribute to the onset of the disease, it can spread through the bloodstream or neural pathway.

Clinical manifestations of herpes simplex

Clinically, it can be divided into two types: original type and recurrent type. The initial incubation period for herpes simplex is 2 to 12 days, with an average of 6 days. HSV can be isolated from almost all visceral or mucosal epidermal sites. In the first infection (whether it is HSV- or HSV-), there is no HSV antibody in the serum of the host during the acute phase. It is often accompanied by systemic symptoms and is often more obvious than recurrent herpes. The original type of herpes simplex skin and mucosal lesions often take 2 to 3 weeks to heal, while recurrent herpes simplex lesions usually disappear within 1 week.

Skin herpes

Occurs at the junction of the skin and mucous membranes. It is more common at the lips, corners, and around the nostrils. Initially, itching, burning or stinging of the local skin leads to congestion and flushing. Later, needle or rice grain-sized clusters of blisters appear, and the basal area is reddish. The blisters do not fuse with each other, but multiple clusters of blisters may appear at the same time. The blisters have thin walls, clear blisters, short-term spontaneous ulceration, erosion, and exudate. Dry crusts after 2-10 days, leaving no scars after exfoliation.

Oral herpes

Herpes and ulcers appear in the oral mucosa, tongue, gums, and pharynx and can spread to the esophagus. The patient had local pain, refusal to feed, and drooling. May be accompanied by fever and swelling of the submandibular lymph nodes and / or cervical lymph nodes. Children and young people are more common.

3. Genital herpes

Mainly caused by HSV- infection. The genitals, perineum, vulva, thighs, and buttocks can all be affected, with herpes, ulcers, and patchy erosions. Males mostly occur in the glans, foreskin, coronary sulcus, penis, and can also affect the scrotum; females are more common in the labia majora, clitoris, vagina, cervix, and the urethra. Homosexuals with a history of anal sex can cause herpetic proctitis, followed by perianal and rectal suppurative infections or groin lymphadenitis.

4. Eye Herpes

Presented as univesicular keratitis and conjunctivitis, most of which are unilateral, often accompanied by affected eyelid herpes or edema and anterior ear lymphadenopathy. Anti-relapse authors can cause corneal ulcers, turbidity, and even blindness caused by perforation. Choroidal retinitis can occur in newborns and AIDS patients.

5. Herpes gangrene

It is a complication of the primary stoma or genital herpes. The virus can enter through the damaged finger epithelium or directly into the finger epidermis due to occupational and other reasons. Herpes lesions often occur at the terminal knuckles and penetrate into the nail bed to form honeycomb necrosis; therefore, local pain is severe, and it is like jumping pain. Accompanied by fever, elbow and axillary lymphadenitis. Dentists and nurses who frequently touch herpes patients with bare hands are at risk for the disease.

6. Herpes eczema

It is caused by chronic eczema, dermatitis and other patients with HSV infection, which is easily misdiagnosed as exacerbation of the original eczema. Sudden viral infections in the skin lesions and surrounding skin, or spread of bloodstream, involving other important organs, further worsen the disease.

7. Newborn herpes

70% of neonatal HSV infections are caused by HSV-II, which are all caused by exposure to reproductive tract secretions at birth; congenital infections are often mothers of primary HSV infection that cause intrauterine infection of the fetus during pregnancy. Fetuses infected intrauterinely can be born prematurely, or have congenital malformations, or mental retardation, the so-called "TQRCH" syndrome. Neonatal infection with HSV can present asymptomatic recessive infections, and can also cause different forms or different degrees of clinical manifestations. Mild cases are only oral, skin, eye herpes, while severe cases are central nervous system infections or even systemic disseminated infections.

8. Disseminated herpes simplex

Disseminated HSV infection is more common in children between 6 months and 3 years of age, and can also be seen in those with primary or secondary immune dysfunction (suppression). Initially manifested as severe herpetic gingivitis, esophagitis, or vulvovaginitis, high fever, and even convulsions, followed by extensive blisters throughout the body, umbilical depression of the top of the blister, and viremia may occur at the same time, causing herpes hepatitis, encephalitis , Pneumonia, gastroenteritis, and adrenal dysfunction.

Differential diagnosis of herpes simplex

It is not difficult to diagnose those with typical herpes damage on the body surface. The most common herpes simplex is recurrent type, and according to the characteristics of clinical lesions, the site of the attack can be diagnosed. It may be misdiagnosed for some rare primary infections, or if the damage is only deep in the cavity (such as the reproductive tract, respiratory tract, etc.), or if there is only visceral herpes damage and no damage to the body surface. This disease is sometimes distinguished from facial shingles, impetigo, and fixed drug eruption.

Herpes simplex treatment

Local skin and mucous membrane limited HSV infection can be treated only with local medications. For patients with severe symptoms, skin lesions, or disseminated infections or important organs, systemic antiviral medications and corresponding symptomatic supportive treatment should be given.

Local treatment

Mainly to astringent, dry and prevent secondary infection. Can be topically applied with 3% phthalobutyl cream, 3% acyclovir eye ointment, and 2% methyl violet solution for topical application, 3 or 4 times a day. If there is a secondary infection, use 0.5% neomycin ointment, 0.5% chlortetracycline eye ointment or mupirocin ointment, davidbon cream, etc. When the erosion is exuding, you can use 3% boric acid solution and 1% aluminum acetate solution to apply a local wet dressing, which can dry the skin, reduce or disappear the pain, and shorten the disease course.

For herpetic keratitis and conjunctivitis, 0.1% herpes cleansing eye drops, 1% acyclovir eye drops, and 0.1% ribavirin eye drops can be used once per 2 hours. Relapsed patients can be treated with 3% acyclovir eye ointment and 0.1% dexamethasone eye drops, which is faster, more effective, and shorter in duration than antiviral drugs alone.

2. Systemic treatment

Oral nucleoside antiviral drugs can be selected. In addition to nucleoside antiviral drugs, non-nucleoside antiviral drugs can also be selected, such as ribavirin, isoprinosine, polymyosin, and interferon, which can be used in conjunction with nucleoside drugs.

Herpes simplex prevention

1. Newborns and those with low immune function, burns and eczema should avoid contact with HSV infection as much as possible.

2. For women with genital herpes, a caesarean section should be performed to avoid infection during fetal delivery.

3. Condoms can reduce the spread of genital herpes, especially during asymptomatic detoxification. Once herpes lesions appear, sexual life should be avoided.

4. It is strictly forbidden to feed infants mouth to mouth.

5. Optional vaccination with HSV vaccine.