The Greek word exánthēma , which can be translated as "efflorescence" , came to late Latin as exanthēma , which in our language led to exanthema . The term is used in the field of medicine to name a type of skin rash .
The rash usually appears along with a warming of the skin . This reddish rash disappears momentarily when pressed with a finger. Diseases such as chickenpox and measles are characterized by rash.
Rashes, therefore, are clinical signs of certain diseases . Its quantity and distribution in the body vary depending on each case. The rash usually appears due to an infection or an allergic reaction.
Maculopapular rashes are the most common. They are made up of papules ( lesions that are raised) and macules (lesions that are flat) that can have various shapes. Purpuric exanthems (with ecchymoses, petechiae, and hematomas) and vesicular exanthems (with blisters and vesicles) are other types of exanthems.
Chickenpox, for example, is caused by the varicella-zoster virus . This disease has a latency period of between two and three weeks before manifesting itself with a flu-like illness. Its development continues with the rash, whose papules turn into vesicles and later into scabs. These injuries can cause permanent scars depending on their evolution and the wounds that the patient generates if they scratch themselves.
As for measles , this viral disease has an incubation period of between four and twelve days. Then the rash appears with a generalized rash throughout the body.
Sudden rash
A disease that arises due to a virus in children between 4 months and 2 years of age is known as exanthema subitum , sixth disease or infantile roseola , although it can occur at other ages. The means of transmission are saliva and blood. On the skin you can see lesions in the form of pink or red dots that turn white when pressed. Initially, they appear on the trunk and neck, but later spread to the extremities and face.
Despite certain similarities in symptoms, exanthema subitum should not be confused with scarlet fever, measles, and rubella , three other exanthematous diseases. A similar reaction can occur in cases of hypersensitivity to drugs.
Regarding the most common cause, this is usually the human herpes virus 6 , but it can also appear as a result of 7 . Within 6, two types are recognized: A and B , the latter being the one that accompanies 99% of cases of sudden exanthema. This disease has an incubation period that ranges from 5 to 15 days and, generally, the reservoir of the virus that causes it is an adult person who has been in contact with it.
It is common for patients with sudden exanthema to experience a high fever that appears without apparent cause, and that lasts between two and three days. It is only when they regain normal body temperature that small pink pimples are noticed, which little by little cover a greater surface of the skin. The rash itself usually does not exceed two days.
Although it does not usually occur, it is possible that certain complications may arise from this infection. The most common is a picture of febrile seizures that occurs in the phase before the appearance of the rash. It is worth mentioning that seizures are usually not serious and that in some patients they occur as a direct result of involvement of the central nervous system. In people who have a compromised immune system, on the other hand, it is normal for cases of hepatitis and encephalitis to arise.