When someone has a rash, then this means that he or she has a change in the skin color or texture. In the most cases rashes are caused by skin inflammation and there are many causes for skin inflammations. Your skin can become itchy, bumpy, scaly or otherwise irritated. There are many different causes for rashes such as certain diseases (such as measles and chickenpox), cosmetics, medications and allergies.
Causes of rash
One of the most common causes for rashes is the contact dermatitis . It is known that the contact rashes are happening when the skin is coming into direct contact with a foreign substance which is causing an adverse reaction that leads to a rash. The resulting rash may be inflamed, red or itchy. Here are some possible causes of contact dermatitis:
- Touching poisonous plants, such as poison sumac, poison ivy or poison oak
- Being in contact with chemicals in rubber, elastic or latex
- Using dyes in clothing
- Using beauty products, soaps and laundry detergent
Also there are some medications which can cause rashes and they form as a result of:
- Photosensitivity to the medication 
- A side effect of the medication 
- An allergic reaction to the medication 
Also there are other possible causes of rashes such as
- RA which is an autoimmune disease that can cause a rash to form on many parts of the body
- Lupus erythematosus which is an autoimmune disease that is triggering the rash on the cheeks and nose. This rash is also known as a butterfly or malar rash.
- Seborrheic eczema which is a type of eczema that most often is affecting the scalp and it causes redness, scaly patches and dandruff. Also it can happen on the nose, mouth and ears. When babies have this condition, then it is known as crib cap.
- Psoriasis which is a common skin condition. It is causing a scaly, itchy and red rash to form along the scalp, joints and elbows.
- Eczema is also known as atopic dermatitis. This is a rash which is primarily happening in people who suffer from allergies or asthma. This rash is often reddish and itchy with a scaly texture.
- A rash sometimes can develop in the area of bug bite. If you have been bitten by a tick, then you should concern about it because they can transmit disease.
Children can also develop rash as a result of illnesses such as:
- Kawasaki disease
- Fifth disease
- Hand, foot and mouth disease
- Scarlet fever
Types of rash
There are some many different types of rash. Below we give you the most common types of rashes and their characteristics:
- Severe Acute Respiratory Syndrome (SARS): 
- Diarrhea, problems breathing, dry cough
- Ebola virus and disease: 
- Unexplained bleeding or bruising
- Diarrhea, muscle and stomach pain
- Fever, headache
- Colorado tick fever: 
- Sudden fever
- Skin pain with faint rash
- Measles: 
- White spots in the mouth
- Commonly develops at the head then spreads to the rest of the body
- Red, itchy bumps
- Chickenpox: 
- Sore throat
- You can have clusters of red and fluid – filled blisters all over the body
- Swelling in the eyes and face
- Rash may appear in the later stages of this condition
- Muscles aches and pain
- Diaper rash: 
- Warm to the touch
- Near the diaper area
- Skin looks red and irritated
- Fungal infections:
- May start as a reddish, itchy and scaly rash
- Itching, swelling, peeling and cracking of the rash
- Bites and stings:
- Itching, numbness and tingling
- Heat, redness and swelling at the site of the bite
- Pain in the bite area or in muscles
- Flea bites:
- Symptoms begin immediately after being bitten
- Usually located on the lower legs and feet
- Itchy, red bump surrounded by a red halo
- Scabies: 
- Raised, white or flesh – toned lines
- Symptoms may take 4 – 6 weeks to appear
- Rash may be pimply, made up of tiny blisters or scaly
- Scarlet fever:
- Feels like sandpaper
- Follows strep throat infection
- Small red bumps
- Fifth disease:
- Rash will appear on the cheeks, then the arms, legs and trunk
- Children are more likely to experience a rash
- Headache, fatigue, low fever, sore throat and nausea
- Rheumatic fever:
- Slightly raised, ragged skin
- Complication of strep throat or scarlet fever
- Small, painless bumps under the skin
 Statescu L, Branisteanu D, Dobre C, et al. Contact dermatitis – Epidemiological study. Maedica (Bucur). 2011;6(4):277–81.
 Korzeniowska K, Cieślewicz A, Chmara E, et al. Photosensitivity reactions in the elderly population: questionnaire-based survey and literature review. Therapeutics and Clinical Risk Management. 2019;15:1111–9.
 Ancuceanu R, Dinu M, Furtunescu F, Boda D. An inventory of medicinal products causing skin rash: Clinical and regulatory lessons. Experimental and Therapeutic Medicine. 2019;18(6):5061–71.
 Almutairi A, Alfaleh M, Alasheikh M. Dermatological manifestations in patients with SARS-CoV-2: A systematic review. Cureus. 2020;12(7):e9446.
 Kourtis AP, Appelgren K, Chevalier MS, McElroy A. Ebola virus disease: Focus on children. The Pediatric Infectious Disease Journal. 2015;34(8):893–7.
 McDonald E, George D, Rekant S, et al. Notes from the field: Investigation of Colorado tick fever virus disease cases — Oregon, 2018. Morbidity and Mortality Weekly Report (MMWR). 2019;68(12):289-90. Retrieved from www.cdc.gov/mmwr/volumes/68/wr/mm6812a4.htm
 Laksono BM, de Vries RD, McQuaid S, et al. Measles virus host invasion and pathogenesis. Viruses. 2016;8(8):210.
 Breuer J, Fifer H. Chickenpox. BMJ Clinical Evidence. 2011;2011:0912.
 Sharifi-Heris Z, Farahani LA, Hasanpoor-Azghadi SB. A review study of diaper rash dermatitis treatments. Journal of Client-Centered Nursing Care. 2018;4(1):1-12.
 Chandler DJ, Fuller LC. A review of scabies: An infestation more than skin deep. Dermatology. 2019;235:79–90.