Difference Between Hives and Rash 

Key Differences – Hives vs Rash
 

The key difference between Hives and rash is that Rash is a general term used to describe a form of skin disease associated with different appearances, texture of the skin as a result of skin damage that occur due to multiple causes such as infections, immune-mediated diseases etc. while Hives or urticaria are specific forms of skin manifestations with a characteristic appearance which are commonly caused by allergy.

What are Hives?

Hives are slightly elevated, reddish, itchy, multiple lesions occurring on the skin. These occur commonly as a result of an allergy. With allergen exposure, it  causes mast cells to release histamine which is a chemical mediator stored inside mast cells. Histamine causes dermal edema giving rise to this typical appearance. Hives occur very rapidly, and it commonly occurs with food allergy. However, some other causes such as pressure and sunlight can cause hives rarely in a certain vulnerable group of people. Hives disappear spontaneously, and they are self-limiting. If hives are associated with life threatening allergic reactions such as angioedema (edema around the mouth) or anaphylaxis, more medical attention is required. Antihistamines can be used for symptomatic relief. Sometimes, a short cause of steroids may be required to relieve symptoms. It is important to avoid exposure to known allergens/causes to prevent recurrences of hives.

What are Rashes?

Rashes are a category of skin disease causing skin damage. Rashes can take many appearances such as macular, popular, maculopapular, exfoliative, plaque forming, etc. Some rashes are inherent diseases affecting the skin such as Eczema and Psoriasis. Some rashes associated with other systemic diseases such as autoimmune diseases, infections, etc. Identification of the typical appearance and the distribution of rashes guide in the diagnosis of associated systemic diseases. Dermatology is the specialty in medicine with regard to the management of rashes. When the rash is severe, affecting deep layers of the skin, it can lead to dehydration, hypothermia, and infections. Rashes need proper attentions by a doctor. Some rashes are short lasting and completely curable. Examples for these are infection associated rashes such as viral exanthema. On the other hand, some rashes are relapsing and not completely curative. Examples are psoriasis and eczema. However, these rashes can be controlled satisfactorily by offering proper treatment.  Treatment for rashes includes local applications such as lotions, creams, and ointments as well as oral treatments.

What is the difference between Hives and Rash?       

Cause

Hives: Hives are caused by allergy in most of the times.

Rashes: Rashes are caused by many causes including infections, autoimmune disease, etc.

Appearance

Hives: Hives are reddish, itchy, round or irregular, multiple lesion occurring rapidly all over the body.

Rashes: Rashes can take many appearances such as macular (flat), popular (elevated), etc.

Associations

Hives: Hives can be associated with other manifestations of allergy such as angioedema, wheezing, anaphylaxis.

Rashes: Rashes can have many associations such as infections and autoimmune diseases.

Treatment

Hives: Hives can be treated with antihistamines and steroids.

Rashes: Rashes can be treated with many different local applications as well as with oral treatment depending on the cause.

Prognosis

Hives: Hives can occur as a single episode or recurrent depending on the underlying cause, and they have a good prognosis in most of the times.

Rashes: Rashes are caused by a variety of causes. Therefore, the prognosis will depend on the exact cause.

 

Image courtesy:

“EMminor2010” by James Heilman, MD – Own work.(CC BY-SA 3.0) via Commons

“Severerash” by Rashy100 at English Wikipedia – Transferred from en.wikipedia to Commons.(Public Domain) via Commons