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A rash, also known as a lesion or dermatitis (Greek for skin inflammation) is a dermatological condition which causes changes in the appearance, texture or color of the skin.

While a rash itself is not a pathological condition, it can be a sign or a symptom indicating a causative disease or disorder. A rash may cause the surface of the skin to become dry, filled with cracks or blisters and make the affected part of the skin very itchy.



While dermatitis is defined as the simple rash, there are other variants of it. Contact dermatitis is caused due to the contact of skin with certain irritant chemicals in the objects we use everyday and certain plants like the Poison Ivy and poison Oak. Irritant dermatitis, a subtype of contact dermatitis is caused by skin contact with acids and alkali present in soaps, perfumes and adhesives. This kind of rash usually looks like a burn.

Allergic contact dermatitis is a result of exposure to substances to which a person’s skin is too sensitive or allergic. In such cases, the rashes may take up to 2 days to appear. Based on the substance, the part of the body and the level of allergy, the rash may vary from a slight irritation to open sores. Overtreatment dermatitis occur as a result of excess medical treatment administered for a different skin condition.

Seborrheic dermatitis is another form of rashes which occurs both in adults and infants. While the milder versions are known as dandruff in adults and cradle cap in infants, there are more serious variants. Normally, this condition causes characteristic white or yellow flakes of skin in places with high oil content such as the inner ear or the scalp. This condition is said to be caused by a type of yeast known as Malessizia or due to an increased production of oil by the skin.

While it seems to recur in families, factors such as excessive stress, inclement weather, irregular usage of shampoos, applying alcohol-based lotions and pre-existing skin conditions increase the chances of infection. It is important to understand that cradle cap among infants is not infectious or a result of unhygienic care. Also, it is not a serious condition and is not caused due to allergies. It is a relatively harmless skin condition.



Other conditions can also lead to formation of rashes. Eczema (or atopic dermatitis) is seen in people with pre-existing asthma or allergic tendencies and causes red, irritating scales on the skin.



Psoriasis is another causative factor which can cause rashes on joints and the scalp. It may also affect fingernails. Other conditions like Impetigo and Shingles can also cause rashes with characteristic appearances.

While different treatments are available for different kinds of dermatitis, there are some precautions which need to be taken when a rash first appears. The rash should not be touched and substances such as soaps, lotions should not be applied on the rash. It is always safer to consult a dermatologist instead of choosing self-medication before it turns ugly.