• What are exanthematous diseases
• Viral exanthematous diseases
• Bacterial exanthematous diseases
• The importance of diagnosis in exanthematous diseases

What are exanthematous diseases

Rash comes from the Greek and means outbreak or outburst. Exanthematous diseases generally manifest themselves with a skin rash , which involves redness, papules of different size and relief, itching . These symptoms are accompanied by other conditions such as fever , loss of appetite , fatigue , headache , abdominal pain , muscle soreness.

Exanthematous diseases are infectious and generally affect young people , often infecting them en masse in the school period in which the social approach is at the highest levels. Since the immune system is not yet complete and efficient in those age groups , some exanthematous diseases are part of the immunological formation process.

Exanthematous diseases are distinguished from each other by their origin (viral or bacterial) and also by their treatment (causal or symptomatic). Diagnosis generally occurs through a physical examination by the treating physician; in case of doubt, a swab is carried out to verify the bacterium involved.

Viral exanthematous diseases

Some exanthematous diseases originate from viruses . In these cases the treatment is symptomatic , to soothe redness, more or less serous papules, itching, fever. It is necessary to wait for the course of the disease in isolation , then withdraw from the social contact of the school in order to avoid contagion.

Pharmacological aids can be used to lower fever, accompanied by  remedies to reduce redness, burning and itching , such as ointments based on aloe vera or calendula and rice starch sponges .

> Varicella : caused by the Varicella-Zoster virus, it is incubated for about 13-17 days and manifests itself with the appearance of red macules which in a few hours evolve into serum-filled papules and progressively spread over various parts of the body. These blisters can create severe itching , which it would be good not to indulge in to avoid causing permanent damage to the skin . The blisters then dry out and leave crusting. The course of chickenpox can vary from 7 to 14 days.

> Measles : caused by the Morbillivirus, it begins with a cold  , followed by the appearance of brownish spots after a few days .

It is highly contagious and mainly affects children, but it can also be insidious for adults who have never been vaccinated. It is transmitted by coughing  and sneezing and nestles both in the mouth and deep in the lungs , where it finds the right environment to proliferate. In addition to this form of direct contagion, there is also an indirect one , if you come into contact with surfaces that have been contaminated by an infected person.

Measles incubation times are about ten days and the concomitant symptoms of the skin rash can be high fever, red eyes , dry cough , plaque in the throat. The course of the disease varies between 7 and 10 days. Measles can be very dangerous if contracted by a pregnant woman , with very serious consequences for the fetus, even death.

> Rubella : caused by the Rubella Virus, it presents with the appearance of red spots all over the body , with possible swelling of the lymph nodes in the neck and ear area. The incubation times are quite long, about 2 or 3 weeks. In addition to the rash, some sort of flu , fever, sore throat , cold, red eyes and joint pains may appear.

Also the transmission of rubella can occur both directly , coming into contact with droplets emitted by stranuti or cough by the infected person, and indirectly by coming into contact with contaminated objects for a short time.

If contracted during pregnancy , rubella can be very dangerous for the unborn child and lead to blindness, deafness, heart problems, lung damage, brain edema. It is therefore important to prevent it with the vaccine . 

> Fifth disease : caused by Parvovirus B19, it is also called infectious erythema  and occurs with skin rash on the arms and legs, cheeks that swell and painful to the touch, accompanied by low-grade fever, headache, sore throat, fatigue .

This infectious disease mainly affects children and young people, but also non-immunized adults. According to the statistics, it has its own seasonality , appearing from winter until the dawn of spring. The incubation times  range from 4 to 21 days, while the duration is around 15 days.

It too can be transmitted directly or indirectly . Since it is easy to confuse it with measles, rubella or fourth disease, sometimes more targeted tests (such as blood tests) are carried out for people who are particularly at risk.

> Sixth disease : caused by Herpes virus 6B, it is also defined as a critical rash and can affect children from six months to two years of age. After an incubation period of between 5 and 10 days, it manifests itself with very high fever, vomiting, diarrhea, swelling of the pharynx, retro-auricular lymph nodes and skin rash all over the body.

After 2 or 3 days it regresses; this is why it is also called 3-day exanthemic fever . Any complications are due to high fever, which can be kept under control with the help of pharmacological aids.

Bacterial exanthematous diseases

There are other exanthematous diseases that originate from bacteria and require causal treatment. It is therefore necessary to deepen the investigation with laboratory tests to identify the triggering bacterium and proceed with the correct antibiotic prophylaxis .

> Fourth disease : probably caused by beta-haemolytic streptococcus type A (but not always ascertained), it is also called ” scarlet fever ” because it has symptoms very similar to those of scarlet fever, but milder. It spreads through direct and indirect contact and the target is kindergarten-age children.

The fourth disease has a course very similar to scarlet fever, with fever, fatigue, rash limited to the cheeks, buttocks and groin, with subsequent desquamation. It regresses quite quickly (4 or 5 days) and often does not require antibiotic therapy .

> Scarlet fever : caused by beta-hemolytic streptococcus type A, manifested by  scarlet rash, fever, sore throat, early stage white strawberry tongue and late stage raspberry tongue , abdominal pain and possible tachycardia. The skin rash presents with small red patches on the neck, armpits, groin, which after 24 hours also affect the rest of the body. After a few days the affected skin begins a peeling process , but without itching .

Scarlet fever affects children between the ages of 5 and 15 , more rarely adults. Transmission can occur both directly, through cough and cold droplets, and indirectly through contact with contaminated surfaces. The incubation times range from 1 to 7 days. Scarlet fever is diagnosed by means of a swab and treated with the administration of antibiotics .

The importance of diagnosis in exanthematous diseases

Exanthematous diseases must always be investigated by the attending physician and not treated with the “do it yourself” , because they generally affect weak subjects, such as children or immunosuppressed who require precise therapies.

It is important to establish whether they are viral or bacterial in nature. Remember that antibiotics have no effect on viruses , but they can further weaken the immune system . Vaccines are the result of great progress in the medical field and serve to enrich the immunological library of the human organism . It is possible to discuss the methods and timing of administration, but certainly not about their validity and the importance of adequate coverage.

Some viral exanthematous diseases, such as measles for example, are particularly mutant because their genomic system is unstable. This means that certain pathologies that were believed to be outdated can also reappear in the population.