A rash by definition means a generally transient appearance of lesions on the skin, with or without relief, sometimes in the form of blisters. It can be redness, patches or pimples. From English rash, a short-lived rash can occur during a disease of infectious or parasitic origin or during drug intoxication. The causes being numerous, it is necessary to carry out a precise diagnosis in order to propose an adapted treatment.

The rash, rash in French, refers to the sudden and transient appearance of pimples or red patches. It can happen that an intolerance to a drug is the cause of the skin rash. The rash often appears during the onset of the first symptoms of an illness and is sometimes accompanied by an increase in temperature, nausea, diarrhea and joint pain. A rash can last from a few hours to a week depending on the cause.

Rashes can be related to several factors:

• a skin problem;
• a more widespread affection of the organism;
• side effects of treatment;
• symptoms of mild or serious illnesses.

When your skin comes into contact with an irritating substance or that you do not tolerate well, it can react with redness or pimples on the affected area, this is called “contact dermatitis”. This sometimes happens with latex, jellyfish, nettles, household products. In pediatrics, an example of a contact rash is “infant diaper rash”: contact of the baby’s bottom with urine, stool or wet diapers can cause redness.

Allergic causes

A rash can be the result of an allergic reaction to:

• a food (crustaceans, fish, eggs, dairy products, nuts, etc.);
• a cosmetic product;
• a medicine (this can also be a side effect);
• an insect bite;
• an animal.

An insect bite, food or medication can cause an acute allergic reaction called angioedema or anaphylactic shock. It is a vital emergency.

Infectious causes

Chickenpox, like measles and rubella are among those mild childhood illnesses where the virus causes rashes. Other viruses can cause rashes, including herpes and shingles. We also note:

• bacterial infections like scarlet fever or typhus;
• AIDS, caused by HIV (human immunodeficiency virus);
• Covid-19 infection can cause hives or frostbite-like rashes. It is, however, an uncommon symptom of the disease;
• chronic inflammatory diseases such as psoriasis or eczema;
• certain heavy treatments such as chemotherapy;
• the stress ;
• exposure to the sun or cold;
• heat, especially during sports, can also cause minor eruptions.

Depending on the cause, rashes can come in very different forms. This phenomenon can spread to the whole body or remain isolated. The spread of lesions can be rapid or very slow. It is therefore important to have them examined in order to obtain appropriate treatment.

How your rash can be treated therefore depends entirely on the type of illness you have. It can be an anti-inflammatory, anti-allergic or anti-infective treatment. Treatments can be local and come in the form of creams, ointments, lotions or powders. They can be oral in the form of tablets, especially in certain allergic or infectious causes.

• In case of drug allergy, the responsible drug will be stopped;
• Antihistamines or corticosteroid creams to relieve itching will be used in case of mild reactions;
• Sometimes intravenous medication and hospitalization will be considered for severe reactions;
• In case of skin allergy, do not apply cream or ointment in self-medication without the favorable opinion of a doctor. You don’t know how your skin will react. Avoid contact with the allergen. You can use a natural treatment to soothe your pain and itching by placing a compress soaked in cold water on your skin lesions.