Skin Rash

Skin is the largest organ covering the entire body from head to toe. It acts as a physical barrier or a protective layer between your body and the outside environment. Hence the skin protects your body from various harmful environmental exposures as well as from dust and infections. However, sometimes this immunity fails which leads to the development of a reaction on the skin in the form of a skin rash. Skin rash can be broadly defined as a specific response to the allergens by the skin which can cause a change in colour and appearance of the skin. Nowadays, drug-induced skin rash is highly prevalent. Whenever you have been prescribed a new drug you should observe for any reaction to that drug. It is mostly due to the drug itself or due to the added binders, colouring agents and stabilizers used in the drug. Therefore, it is essential to seek immediate medical help, stop using that drug and also you should note the drug for future references to alert your doctor.

Skin rash is itself a symptom of an underlying cause or conditions. Skin rash along with some other symptoms can help in the diagnosis of the situation. Symptoms that usually present with a skin rash are:

• Itching
  Itching of skin where rash has developed can be present in many conditions. Mostly it is related to allergic conditions and sometimes drug-induced or infectious in origin.
• Fever
  Skin rash may be an initial symptom followed by fever or sometimes reverse is seen in diseases caused due to viruses, bacteria, fungi, and parasites. These are some of the examples of diseases, which show fever with a skin rash:
  • Dengue caused by the virus of the same name and is transmitted through mosquitoes. Skin rash is due to the rupture of capillaries beneath the skin which appears like red spots.
  • Rheumatic fever caused due to bacterial infection in which the infection affects the heart and all the symptoms are related to a cardiac disorder.
  • Candidiasis is a fungal infection which is accompanied by a white discolouration of the skin due to ingrowth of the fungus.
  • Scabies is caused due to a parasite wherein unhygienic conditions let the parasite settle into the web spaces of fingers and also induces night-time itching.
• Redness
  A rash is also accompanied by redness and sometimes, this redness starts spreading to different parts of the body.
• Swelling
  Sometimes rash converts into swelling or bulging which may appear like water-filled blisters as in the case of bullous pemphigus. Sometimes they turn scaly like in case of psoriasis which presents with a rash initially and then converts into shiny white scales. The rash spreads with time all over the body and bleeds on peeling off the scales.  

​​Causes

There are many causes of a skin rash, however, sometimes, the cause remains unidentified. Following are some of the common causes of skin rash:

• Drugs
  Anti-convulsants, HIV drugs (Human immunodeficiency virus), and some antibiotics can be responsible for a skin rash.
• Food allergy
  You may have a food allergy to certain food items. Diagnosis can be difficult if a previous history of allergy is unknown. Keen observation of food intake and keeping track of each reaction can help find the exact food to which you are allergic. Some people, for example, are allergic to peanuts, mayonnaise.
• Exposure to toxic chemicals
  Toxic chemicals released from industries into the environment can react with skin and cause rash. These chemicals may be in the form of waste products or noxious gases.
• Long-term exposure to sunrays
  Heat rash also called prickly heat is due to a prolonged exposure to harmful ultraviolet rays of the sun as well as extreme heat, generally seen in summer.
• Infections
  Infection due to microorganisms can lead to skin rash along with some other symptoms like fever, rash spread, pus or fluid discharge among others. Viral infection such as chikungunya and hand foot mouth disease are some of such diseases. Leprosy which is a bacterial infection also presents with generalized rash and nerve involvement.
•  Other diseases
  There are certain chronic skin diseases, which usually present as a skin rash. These include eczema, dermatitis, psoriasis, impetigo, systemic lupus erythematosus (SLE) among others. In some cases, the skin rash may also get infected, bleed, or ooze a clear watery fluid.
• Insect bite
  Small insects hardly visible to eyes can also be responsible for an allergic rash as insect bite releases toxins which can cause irritation to skin and rash.
• Diaper rash
  Seen in small babies wearing diapers for a long time. This rash is generally caused due to wetness and irritation of diaper or may be due to infection.
• Miscellaneous
  Skin rash can result from many other causes such as living in unhygienic conditions, impurities in water, exposure to heavy metals, harsh detergents while washing clothes and utensils, and exposure to some species of grass.

Risk factors

These include:

• History of Asthma
  It is a lung disease in which a person faces difficulty in breathing due to the inflammation of the lung(s). It is a type of allergic condition which may also cause skin rash due to the involvement of allergens.
• Children
  Children of less than 12 years of age are extremely prone to allergies and infections due to weak immunity.
• Unhygienic lifestyle
  People who live in unhygienic conditions or do not take care of their hygiene such as proper bathing, washing of hands and wearing clean clothes are at risk of having a skin rash.
• People who handle laundry
  People washing clothes daily and are in continuous contact of detergents may be at a risk of detergent-induced allergic reaction also known as allergic dermatitis.
• Workers
  People working in heavy metal, chemical or leather industries or working in the intense heat and extreme weather conditions like in construction of coal tar roads are more prone to getting a skin rash.

Skin rash is mostly preventable as most of the causes can be avoided. Certain important points to note for preventing such a rash are:

• Taking care of hygiene by regularly bathing, cutting nails, wearing clean clothes, and washing hands before eating meals and after using the toilet.
• Protection from intense heat and sun by wearing a sunscreen and using scarfs and full sleeves clothes.
• Avoiding walking barefoot on grass. It may be wild grass and can lead to a rash or redness of the skin.
• Protecting yourself from chemicals and heavy metals. If you are working in chemical, leather or heavy metal industry, wear protective clothing such as jackets, gloves and long boots.
• If you have had a skin rash due to some food or medicine, make sure you stay away from it in the future.

Diagnosis can be prompt and straightforward in situations when your doctor can easily identify the symptoms. Sometimes, however, laboratory tests may be required. A diagnosis is established by:

• Detailed history
  History includes personal history in which your doctor will ask you about your diet, habits, and daily routine to get some clue about the cause of skin rash. Occupational history to know about any cause related to your work.
• Complete blood count
  To confirm if the skin rash is due to an infection. For example, there will be an increase in white blood cells in case of any infections.
• Skin patch test
  Your doctor may advise you to test the part of skin where rash has not developed which is mostly done to confirm the diagnosis of the diseases like dermatitis and psoriasis. In this method, different allergens are used to check for any reaction which can induce allergy.
• Scratch test
  In this test, your doctor will scratch a part of your skin with the help of a sterile needle containing an allergen to check for any allergic reactions.
• Test for different infections
  On observing other symptoms along with a skin rash like fever, swelling and itching, your doctor may carry out tests for certain infections such as dengue, scabies, and chikungunya.

Treatment of skin rash depends on the underlying cause. In most cases, the rash goes away with some home remedies or use of over the counter medications such as calamine lotion. For severe rash and for a rash that is accompanied by an underlying disease, specific medications are required.

• Home remedies
  • Many times, a skin rash does not require any treatment and it wanes off on its own. For example hand, foot and mouth disease caused by a virus in children less than 5 years of age needs only rest. However, if skin rash persists for more than a day or is associated with pain, fever, swelling, and itching, it should not be ignored and you must seek immediate medical advice to find out the cause.
  • Wash your rash with mild soaps that are free of harsh chemicals.
  • Use ice packs on the rash to soothe the rash and relieve any redness.
  • Use petroleum jelly on the rash. This can help in soothing your skin.
  • Avoid using hot water while taking a bath and while cleaning the affected area. It may aggravate the rash and increase irritation and redness.
  • Avoid use of band-aid or any other dressing material to cover the rash and try to keep it open if possible to avoid any friction.
• Treatment of rash
  Your doctor may prescribe medications, depending on the underlying cause of the rash. These include:
  • Anti-allergic drugs may be prescribed by your doctor in case of suspected allergies from food, drug, metals or insect bites. In most of the cases, one to two doses of anti-allergic tablets is sufficient to treat the rash.
  • Anti-inflammatory drugs can be prescribed in the case of redness, pain or swelling associated with the rash.
  • To treat infections, antibiotics such as antibacterial, antiviral, antifungal and anti-parasitic drugs may be prescribed.
  • Topical anti-histamine or steroid creams and ointments may be prescribed to relieve redness, itching, and swelling.
  • In case of severe skin rash, your doctor may prescribe steroid injections.

Lifestyle management

In people who are prone to skin rash due to food allergies or cosmetics, avoiding the allergens and reading labels on foods and skin care products can be very helpful in preventing skin rash in the future. Applying sunscreen while stepping out in the sun can prevent photo-allergy and heat rash. Maintaining adequate hygiene by taking daily baths, wearing clean clothes, trimming nails and washing hands can help in preventing infections and skin rash.

Prognosis

Recovery from a skin rash is generally effective as most of the conditions are treatable and some are self-limiting. In rare cases, serious complications may be associated causing life-threatening consequences.

Complications

Generally, if the underlying disease is diagnosed and treated in time, a skin rash does not lead to any complications. Sometimes the disease but not the skin rash may be fatal and skin rash may be just an initial symptom of the condition. Skin diseases like pemphigus vulgaris, toxic shock syndrome, and Stevens-Johnson syndrome are some examples.