Sudden Rash

What is Sudden Rash?

Sudden rash is an acute viral infection of infants or young children, usually initially manifested by high fever with no local symptoms and subsequent appearance of rubella-like rash (spotted papular rash). Sudden rash is most common among children from 6 to 24 months, the average age is about 9 months. Less often, older children, adolescents and adults may be infected. Sudden rash has a number of other names: pediatric roseola, pseudorasinium, sixth disease, 3 day fever, roseola infantum, exanthema subitum, pseudorubella .. It is officially called sudden rash after the rash appears suddenly (immediately after the fever), this disease is usually called sudden skin rash. To distinguish a sudden rash from other childhood diseases with the presence of a skin rash, it was once called the “sixth disease” (as it usually became the sixth disease in young children and lasted about six days), but this name is almost forgotten.

Causes of Sudden Rash

A sudden rash is caused by the herpes virus 6 (HHV-6), which was isolated in 1986 from the blood of people with lymphoproliferative diseases. and less commonly the herpes virus 7 (HHV-7). HHV-6 was first detected by Salahuddin et al. in 1986 in adult patients with lymphoreticular diseases and infected with human immunodeficiency virus (HIV). Two years later, Yamanishi et al. isolated the same virus from the blood of four babies with congenital roseola. Although this new virus was originally found in B-lymphocytes of immunocompromised adult patients, it later became clear that it has an initial affinity for T-lymphocytes, and its original name – human B-lymphotropic virus (HBLV) – was changed to HHV-6. HHV-6 is a member of the genus Roseolovirus, a subfamily of beta-Herpesvirus. Like other herpes viruses, HHV-6 has a characteristic electron-dense core and icosahedral capsid, surrounded by a shell and outer membrane, the location of important glycoproteins and membrane proteins. The main component of the cell receptor for HHV-6 is CD46, which is present on the surface of all nuclear cells and allows HHV-6 to infect a wide variety of cells. The main goal of HHV-6 is a mature CD4 + cell, but the virus can infect natural killer cells (NK), gamma-delta T-lymphocytes, monocytes, tree-like cells, astrocytes and various T and B cell lines, megakaryocytes, epithelial tissue, and others. HHV-6 is represented by two closely related variants: HHV-6A and HHV-6B, which differ in cell tropism, molecular and biological features, epidemiology and clinical associations. Roseola and other primary HHV-6 infections are due solely to option B. Cases of primary infection associated with option A are still to be analyzed. HHV-6A and HHV-6B are closest to human herpes virus type 7 (HHV-7), but some amino acids are similar to human cytomegalovirus (CMV).

Pathogenesis During Sudden Rash

Sudden rash is spread from person to person, most often by airborne droplets or by contact. The peak of the incidence – spring and autumn. Acquired HHV-6 infection occurs mainly in infants 6-18 months of age. Almost all children are infected at the age of three and retain immunity for life. Most revealing is that HHV-6 infection, acquired in childhood, leads to a high incidence of seropositivity in adults. In the United States of America and many other countries, almost all adults are seropositive. The underlying transmission mechanisms for HHV-6 are not well understood. HHV-6 persists after primary infection in blood, respiratory secretions, urine, and other physiological secretions. Apparently, adults, carriers of HHV-6, which are in close contact with them, become the source of infestation of infants; Other modes of transmission are also possible. Relative protection of newborns against primary infection as long as there are maternal antibodies indicates that serum antibodies provide protection against HHV-6. Primary infection is characterized by viremia, which stimulates the production of neutralizing antibodies, which leads to the cessation of viremia. Specific IgM antibodies appear during the first five days from the onset of clinical symptoms, for the next 1-2 months, IgM decreases and is not detected further. Specific IgM may be present when an infection is reactivated and, as many authors indicate, in a small amount in healthy people. Specific IgGs increase during the second and third weeks, with an increase in their avidity in the future. IgG to HHV-6 persist throughout life, but in lower amounts than in early childhood. Antibody levels can fluctuate after a primary infection, possibly as a result of reactivation of a latent virus. A significant increase in the level of antibodies, according to some scientists, is observed in the case of infection with other viruses with similar DNA, for example, HHV-7 and CMV. In the observations of some researchers it is indicated that in children for several years after the primary infection a fourfold increase in IgG titer to HHV-6 can occur again, sometimes due to acute infection with another agent, it is impossible to exclude the possible reactivation of latent HHV-6. The literature describes that it is possible to reinfection with another variant or strain HHV-6. Cellular immunity is important in controlling primary HHV-6 infection and subsequently in maintaining the latent state. Reactivation of HHV-6 in immunologically compromised patients confirms the importance of cellular immunity. The acute stage of primary infection is associated with increased NK cellular activity, possibly through IL-15 and IFN induction. In vitro studies have noted a decrease in viral replication under the influence of exogenous IFN. HHV-6 also induces IL-1 and TNF-a, suggesting that HHV-6 can modulate the immune response during primary infection and reactivation by stimulating the production of cytokines. After the primary infection, the persistence of the virus is maintained in a latent state or as a chronic infection with the production of the virus. The components of the immune response important in controlling chronic infection are unknown. Reactivation of the latent virus occurs in immunologically compromised patients, but can also occur in immunocompetent people for unknown reasons. HHV-6 DNA is often detected after primary infection in mononuclear cells of peripheral blood and secrets of healthy people, but the main location of latent HHV-6 infection is unknown. Experimental studies conducted by scientists show that HHV-6 latently infects monocytes and macrophages of various tissues, as well as stem cells of the bone marrow, from which it subsequently reactivates.

Symptoms of Sudden Rash

The disease is not very contagious, the incubation period of the disease is 9-10 days. Signs and symptoms of HHV-6 (or HHV-7) infections may vary depending on the age of the patient. In young children, the temperature usually suddenly rises, irritability, an increase in the cervical and occipital lymph nodes, runny nose, eyelid edema, diarrhea, a small injection in the throat, sometimes exanthema in the form of small maculopapular rash on the soft palate and uvula (Nagayama’s spots), hyperemia and conjunctival swelling of the eyelids. Within 12-24 hours after the temperature rises, a rash appears. Older children who develop HHV-6 (or HHV-7) infection most often have symptoms such as high fever for several days, it is possible, a runny nose and / or diarrhea. Older children are less likely to have a rash. The temperature during fever can be quite high, an average of 39.7 C, but it can also rise to 39.4-41.2 C. Despite the high temperature, the child is usually active. The temperature drops critically, usually on the 4th day. The exanthema appears when the temperature drops. Sometimes a rash is observed before the fever goes down, sometimes after the child has a fever for a day. Rash of roseolous, macular or maculopapular nature, pink in color, up to 2-3 mm in diameter, they turn pale when pressed, rarely coalesce, are not accompanied by itching. Rashes usually appear immediately on the body and then spread to the neck, face, upper and lower limbs, in some cases they are located mainly on the body, neck and face. Rashes persist for several hours or for 1-3 days, disappear without a trace, sometimes rash as erythema is noted. Primary HHV-6 infection in newborns is also manifested by sudden exanthema. It can be observed in children of the first three months of life, including newborns, its clinical manifestations are generally similar to those of older children, but it is easier to proceed. A febrile state with no local symptoms is the most common form, but the rise in temperature is usually lower than in older children. According to the literature, more frequent manifestations of primary HHV-6 infection are cases of asymptomatic infection, in which DNA of HHV-6 is detected in mononuclear cells of peripheral blood after birth or in the neonatal period. In some patients, HHV-6 DNA persists in peripheral blood cells for some time, followed by the development of manifest primary infection HHV-6. HHV-6 infection is associated with a variety of manifestations. Some scientists suggest HHV-6 as a cause of chronic fatigue syndrome, others suggest multiple sclerosis, polyorgan insufficiency syndrome, pink lichen, hepatitis, viral hemophagocytosis, idiopathic thrombocytopenic purpura, oversensitivity syndrome to drugs, especially antibacterial. However, these data are controversial and require further in-depth study.

Complications of sudden rash

Complications occur with sudden exanthema quite rarely, with the exception of children with a reduced immune system. People with a healthy immune system, in general, develop lifelong immunity to HHV-6 (or HHV-7).

Diagnosis of Sudden Rash

Blood test: leukopenia with relative lymphocytosis. Serological reactions: detection of IgM, IgG to HHV type 6 (HHV-6) Serum PCR on HHV-6. Differential diagnosis: rubella, measles, erythema infection, enterovirus infection, otitis, meningitis, bacterial pneumonia, drug rash, sepsis.

Treatment of Sudden Rash

Do I need to see a doctor if the child is sick with a sudden exanthema?

Yes, that’s a good idea. A child with a fever and rash should not be in contact with other children before being examined by a doctor. After the disappearance of the rash and fever, the child can return to normal life.

Treatment of fever

If the temperature does not cause inconvenience to the child, then treatment is not necessary. There is no need to wake the child for the treatment of fever, unless instructed by the doctor. A child with a fever should be in a comfortable environment and should not be too warmly dressed. Excess clothing may cause a rise in temperature. Bathing in warm water (29.5 C) can help reduce fever. Never rub child (or adult) with alcohol; alcohol fumes can create numerous problems if inhaled. If the baby is trembling in the bath, the temperature of the bath water should be increased. High fever with sudden rash may trigger seizures. Fibril spasms are common among children from 18 months to 3 years. They occur in 5-35% of children with sudden exanthema. Seizures may look very frightening, but are usually not dangerous. Fibril spasms are not associated with prolonged side effects, damage to the nervous system or brain. Anticonvulsant drugs are rarely prescribed for treatment or prophylaxis with increasing body temperature. What to do if a child has convulsions caused by a fever in a sudden rash: – Keep calm and try to soothe the child, loosen the clothes around the neck. – Remove sharp objects that can cause harm, turn the child on its side, so saliva can flow from the mouth. – Put a pillow or a rolled-up coat under the child’s head, but do not put anything in the child’s mouth. – Wait for the cramps to pass. Children are often drowsy and can sleep after cramps, which is quite normal. After seizures, you need to consult a doctor so that the child must be examined. A rash on a sudden rash occurs when the fever is reduced (fever). A rash appears on the neck and torso, especially in the abdomen and back, but may also appear on the arms and legs (limbs). The skin becomes reddish and temporarily turns pale when pressed. The rash does not itch and does not hurt. She is not contagious. The rash passes in 2-4 days and does not return. The prognosis is favorable.

Preventing Sudden Rash

Prevention not developed; the patient is recommended to isolate until the clinical manifestations of the disease disappear.

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