My feet often get blisters

Some people will feel that blisters always grow on the soles of their feet, and then they will feel that their soles become very painful. This disease will also have a certain incubation period. It takes about 12 days for the patient to gradually feel the appearance of symptoms. If this is the case, it will become very painful and even accompanied by symptoms such as nausea and vomiting.

The incubation period of the disease is 12 to 21 days, with an average of 14 days. The onset is relatively acute. Older children and adults may have prodromal symptoms such as fever, headache, general fatigue, nausea, vomiting, abdominal pain, etc. before the rash appears. In children, the rash and systemic symptoms appear at the same time.

The rash appears within 24 hours of onset, first on the scalp and compressed parts of the trunk, with a centripetal distribution. At first, it is a small pink macule, which quickly turns into a round tense blister the size of a rice grain to a pea, with a noticeable red halo around it, and the center of the blister is umbilical. Mucous membranes are also often invaded, such as the oral cavity, pharynx, conjunctiva, vulva, and anus.

During the eruption period of 1 to 6 days, the rash appears in batches one after another. The skin lesions evolve from small red maculopapules → blisters → scabs → descending, and no scars are left after descending. There is obvious pain and itching during the blister stage, and if secondary infection occurs due to scratching, slight indentations may be left. Weak people may develop high fever, and about 4% of adults may develop disseminated varicella and varicella pneumonia.

The clinical manifestations of varicella include bullous varicella, hemorrhagic varicella, neonatal varicella, adult varicella, etc. In addition, if chickenpox is infected during pregnancy, it can cause fetal malformation, premature birth or stillbirth.

The disease is caused by infection with the varicella-zoster virus (VZV). Varicella-zoster virus belongs to the Herpesviridae family. It is a double-stranded DNA virus with only one serotype. There are at least eight types of viral glycoproteins, which determine the pathogenicity and immunogenicity of the virus. The virus has very weak survival ability in the external environment, is not resistant to heat and acid, and can be inactivated by disinfectants such as ether. Humans are the only host of the virus, and patients are the only source of infection. The infectious period is generally from 1 to 2 days before the rash appears until the herpes is completely scabbed. Immunodeficient patients may be contagious throughout the course of the illness. Children may also develop chickenpox if they come into contact with someone with shingles, as the two have the same cause.

Chickenpox is highly contagious, and the main routes of transmission are respiratory droplets or direct contact. After the virus infects the human body, it first proliferates and replicates in the local lymph nodes in the nasopharynx for 4 to 6 days, then invades the blood and spreads throughout the body, causing lesions in various organs. The lesions of this disease are mainly in the spinous cell layer of the skin. The cells swell and degenerate to form cystic cells with eosinophilic inclusion bodies in the nucleus. Herpes is formed after cell lysis and infiltration of tissue fluid. The blister fluid contains large numbers of infectious virus particles. Blisters are also common on the mucosal surfaces of the oropharynx, respiratory tract, gastrointestinal tract, conjunctiva, and vagina.

People of any age can be infected with the varicella-zoster virus, with infants, preschoolers and school-age children being more likely to be infected, and infants under 6 months old being less likely to be infected. The spread of varicella among susceptible populations depends mainly on factors such as climate, population density and medical and health conditions.