What is arm rash?
Rash is a symptom that causes the affected area of skin to turn red and blotchy and to swell. A rash may cause spots that are bumpy, scaly, flaky, or filled with pus. Rashes can vary in location, pattern and extent and may occur in any area of the body. An arm rash can have a variety of causes, and it may indicate something occurring around the arm itself or suggest a systemic (body-wide) condition.
Contact dermatitis (skin inflammation) is caused by an adverse reaction to something that touches the skin, including chemicals found in detergent, soap or a fragrance. For example, you may develop a rash on your arm when you wear a shirt that was washed with a particular detergent or treated with a chemical. Metal, such as jewelry, can also cause arm rash. Other forms of contact dermatitis include exposure to certain plants, such as poison oak or ivy, an animal bite, or an insect sting. Lyme disease is caused by tick bite and can first appear as a circle with a bull’s-eye pattern, then progress to a rash. Rocky Mountain spotted fever is another tick-borne condition that may start with a rash on the arms and legs, followed by fever and other flu-like symptoms.
Allergies to food and medications are potentially serious sources of rash. Peanuts, shellfish, strawberries and avocados are just some of the foods that can trigger allergic reactions. These foods may cause mild reactions; however, in some cases, reactions could develop into potentially life-threatening conditions characterized by vomiting, difficulty breathing, or swelling. Allergic purpura is a serious, often life-threatening allergic reaction that can cause a skin rash but can also affect the joints, gastrointestinal tract, and kidneys.
Rashes may also be associated with skin conditions, such as eczema, psoriasis and impetigo. Some of these are chronic skin conditions that may flare up for a time, then resolve. Other causes for rash include autoimmune disorders that occur when the body is attacked by its own immune system, which normally serves to protect it from foreign invaders (antigens). Many viruses that occur during flu season, or those associated with childhood diseases, such as chickenpox or measles, can produce rash.
Rashes can be caused by an allergic reaction to food, medications, lotions or detergents. These reactions can range from mild to potentially life threatening, especially if swelling and constriction of breathing occurs, which could indicate anaphylaxis. Seek immediate medical care (call 911) if a rash is accompanied by any serious symptoms, including swelling of the face, swelling or constriction of the throat, difficulty breathing, fainting, change in level of consciousness or alertness, pale skin, or purple rash.
Seek prompt medical care if a rash is persistent and causes you concern.
What other symptoms might occur with arm rash?
Arm rash may be accompanied by other symptoms, depending on the underlying disease, disorder or condition. Certain conditions that cause arm rash may also involve other body systems.
Related localized symptoms that may occur along with arm rash
Arm rash may be accompanied by other localized symptoms including:
- Pus or discharge
- Redness, warmth or swelling
- Scale formation
- Tenderness or pain
Other symptoms that may occur along with arm rash
Arm rash may accompany symptoms related to other body systems including:
- Fever and chills
- Joint stiffness and pain
Serious symptoms that might indicate a life-threatening condition
In some cases, arm rash may be a symptom of a life-threatening condition that should be evaluated immediately in an emergency setting. Seek immediate medical care (call 911) if you, or someone you are with, have arm rash along with other serious symptoms including:
Change in level of consciousness or alertness, such as passing out or unresponsiveness
- Fever and chills
- Joint pain and stiffness
- Purple rash
- Respiratory or breathing problems, such as shortness of breath, difficulty breathing or inability to breathe, labored breathing, wheezing, or choking
- Sudden swelling of the face, lips or tongue
- Tightness or constriction in the throat
- Worsening of symptoms despite treatment
What causes arm rash?
Arm rash may have many possible causes, including allergens (agents that cause allergies), infections, autoimmune disorders, or other causes, such as stress.
Allergic or inflammatory causes of arm rash
Arm rash may be caused by contact dermatitis. Common triggers include:
- Cosmetics, dyes or detergents
- Industrial chemicals, such as those found in elastic, latex and rubber
- Metallic substances such as jewelry
- Poison ivy or oak
Other allergic causes of arm rash include:
- Eczema (skin disorder causing scaly or blistering rashes that may be caused by allergy)
- Food allergies (allergic reactions to certain foods)
- Insect bite allergy such as a bee sting
Infectious causes of arm rash
Arm rash can also be caused by infections including:
- Chicken pox or shingles
- Eczema (skin disorder causing scaly or blistering rashes that may be caused by infection)
- Lyme disease (inflammatory bacterial disease spread by tick bites)
- Meningitis (infection or inflammation of the sac around the brain and spinal cord)
- Pityriasis rosea (a rash resembling the shape of a pine tree)
- Rocky Mountain spotted fever
Autoimmune causes of arm rash
Arm rash can also be caused by autoimmune disorders including:
- Kawasaki disease (rare, serious pediatric disorder characterized by inflammation of blood vessels, high fever, rash, and mucous membrane changes)
- Psoriasis (thick scaly plaques sitting atop a reddened base)
- Systemic lupus erythematosus (disorder in which the body attacks its own healthy cells and tissues)
Other causes of arm rash
Arm rash can be caused by other conditions including:
- Extreme cold or heat
- Wearing close-fitting clothes for an extended period of time (occlusive dermatitis)
Serious or life-threatening causes of arm rash
In some cases, rash may be a symptom of a serious or life-threatening condition that should be evaluated immediately in an emergency setting. These include:
- Allergic purpura
- Anaphylaxis (life-threatening allergic reaction)
Questions for diagnosing the cause of arm rash
To diagnose your condition, your doctor or licensed health care practitioner will ask you several questions related to your rash including:
- When did the rash begin?
- Are you taking any medications?
- Do you have any known allergies?
- Did the rash start in one location and spread to another?
- Does the rash cause any itching or scaling?
- Do you feel otherwise healthy?
- Have you tried any new products recently, such as soaps, perfumes, sprays or detergents?
- Have you spent a lot of time outdoors lately?
What are the potential complications of arm rash?
Because arm rash may be due to serious diseases, failure to seek treatment can result in serious complications and permanent damage. For example, infectious diseases, such as mumps or measles, can lead to rare but serious complications, including miscarriage, hearing loss, and serious brain infections, such as encephalitis or meningitis. Lyme disease can progress to cognitive and functional impairments.
Once the underlying cause of your rash is diagnosed, it is important for you to follow the treatment plan that you and your health care professional design specifically for you to reduce the risk of potential complications including:
- Cognitive difficulties
- Meningitis (inflammation or inflammation of the sac around the brain and spinal cord)
- Miscarriage or stillbirth
- Permanent hearing loss
Secondary infections, which may develop from scratching and related skin trauma