Top 10 Causes of Itching
By Sanaz Majd, MD
Since we have been on a roll reviewing some of the most potentially embarrassing medical conditions in the last several issues, let’s add “itching” to the list. When severe enough, it interferes with sleep, with your daily duties at home or work, and ultimately, your mental state. It can really impair quality of life.
Unfortunately, it is also one of those symptoms where the cause may be a challenge to pinpoint, as numerous medical conditions spanning various organs can cause itching.
Here are the ten most common causes of itching:
1. Allergic Reactions: Allergic reactions often cause “urticaria,” a distinct, visible rash otherwise known as “hives.” These are typically pink/red, raised spots that appear and disappear within the same day on various parts of the body. They can be caused by certain hygiene products, such as detergent, shampoo, soap, or moisturizer, but also by consumed foods, such as nuts, seafood, and exotic fruits.
2. Medication Side Effects: A “drug rash” can be anything from mild to severe, and can occur during a medication’s usage or after it is discontinued (such as a few days after a course of antibiotics). A more feared, but rare, drug reaction called “Stevens-Johnson syndrome” causes a painful rash with scaling and peeling, along with blisters in the mouth, nose, and genitals. It’s severe enough to land patients in the hospital. Certain medications are more prone to cause allergic reactions, such as sulfa containing antibiotics and penicillins—another good reason for why we should avoid antibiotics unless they are clearly indicated. However, any medication can cause an allergic reaction, even one that you’ve been taking on a chronic basis.
3. Dry Skin: Dry skin is one of the most common causes of skin itching. It seems so simple, but it is very real. It is especially prevalent in dry climates like Southern California. And it tends to be worse in the wintertime. The answer to it is fortunately a rather simple one—moisturize. Finding a good oil-based moisturizer and applying it several times a day is often sufficient enough to keep itching at bay. Minimize hot water contact as much as possible, limit showers to 5 minutes or less, and use a mild moisturizing soap like Dove or Cetaphil.
4. Eczema: It is more common in those with asthma and allergies—the genes tend to be inherited together. Eczema is common on the face in infants, but rarely seen there in adults, for whom it most often affects the body, the outside of elbows, and the back of the knees. Eczema is a red/pink, thick, scaly rash, with scratch marks often seen within the rash. Mild cases often respond well to a topical steroid cream.
5. Contact Dermatitis: The word “derm” refers to the skin and “itis” means inflammation; therefore, “dermatitis” simply means the inflammation of the skin. Also, the word “contact” denotes direct skin contact with an allergen that causes a reaction. Therefore, it’s a more localized rash at the site of the contact made with the skin, and not just all over as is often seen with hives. A classic example is poison ivy—contact with this nasty plant can cause a rash and, hence, a rather severe itch at the site of contact. But other common culprits include: nickel and metals (especially on pant belts), cleaning solutions and chemicals (especially on hands), cosmetics, and various topicals. Treatment is also a steroid cream.
6. Fungal Infections: I have reviewed some of these in more detail in a recent issue of Peyk, but they include ringworm, candida intertrigo, athlete’s foot, and yeast vaginitis. Ringworm, called “tinea,” can occur anywhere on the body and consists of round coin-like spots with raised red edges and some clearing of color in the center. They tend to be itchy, but only mildly. Candida is a type of fungus and “intertrigo” refers to the fungal overgrowth that occurs in between the folds of the skin—in the groin, underneath the breasts in women, and underneath the abdominal fold. It tends to be very itchy and diffusely red within those folds. And athlete’s foot appears as scaling and itching on the bottom of the feet and in between and over the toes. Over-the-counter (OTC) anti-fungal creams, prescription powders, and oral pills are several ways to treat these conditions. Fungus is stubborn, often requiring daily treatment for weeks to resolve.
7. Insect bites: Insect bites, like those from fleas and mosquitos, are often red and small, few, and in close proximity in a localized region. Fleas tend to bite the lower extremities, while mosquitos bite any skin that is exposed. The itching is often mild/moderate in severity. When mild enough, most people can use OTC hydrocortisone cream, but more potent prescription steroid creams can be used for more severe itching.
8. Psoriasis: Psoriasis is an autoimmune disorder; this refers to the group of inherited disorders that causes the immune system to produce proteins that cause it to attack itself, thinking that the parts are foreign. Psoriasis attacks the skin and sometimes joints. The rashes have a distinct appearance—red areas of the skin with a thick overlying silver or white scale. The itch is often very mild or minimal, more of a visible rash than it is an itch.
9. Systemic Reasons: Less commonly, itching everywhere can signify a more systemic, or generalized, medical condition. This often means the culprit has entered the blood stream. These conditions include liver disease, kidney disease, HIV, and cancer. A simple blood test can rule out some, but not all, of these causes. Also, make certain you have completed all of your preventative screening tests for your age group (such as pap smear, colonoscopy, mammogram, etc.).
10. Scabies: This is the rash induced by mites that crawl underneath the skin. The itch is often very severe, affecting numerous parts of the body. It also particularly enjoys folds of the body, such as the groin, neck, breasts, armpits, and in between the fingers and toes. Interestingly, for many, it is much more of an itch and less so a visible rash. It is contagious, so family members are often eventually affected. Scabies definitely warrants a visit to the doctor, and the treatment is a prescription topical.
As a side note, viruses can also cause an itchy rash; one classic example is chicken pox, albeit less common now due to vaccines prevention.
UNDERSTANDING YOUR SYMPTOMS
Here are some vital points to help you and your doctor delineate the cause of your itching:
1. Severity: How severe is it? Causes of mild rashes, like dry skin and ringworm, present quite differently than severe ones, like scabies and allergic reactions.
2. Rashes:
Is there a visible rash? Dry skin and early scabies may not present with much to see—they are simply an itch without much of a rash—whereas psoriasis and intertrigo have distinct appearances that cannot be missed.
3. Symptoms & History: It’s important to note the presence of other symptoms or key parts of the history, such as:
Lip, tongue, and throat swelling often indicate allergic reactions. They can also be emergent symptoms that require immediate treatment.
Initiation of new medications, products, or foods.
If there are other family members or close contacts with similar symptoms. Infectious causes of itching can do this, such as scabies and viral syndromes.
ITCHING RED FLAGS
Itching, especially when mild and fleeting, is more often benign and not serious. However, there are certain instances that should prompt you to seek attention right away:
Lip, tongue, and throat swelling
Jaundice (yellowing of the skin or white part of the eyes)
Unintentional weight loss
Severe fatigue
Rapidly progressive rash
Blisters or ulcerations
Fevers
Affected close contacts
And in general, of course, anything that is more than just mild in severity, persistent, or recurrent should also be evaluated. Always err on the side of caution—it’s always better to be safe than sorry.
Please note that all content here is strictly for informational purposes only. This content does not substitute any medical advice and does not replace any medical judgment or reasoning by your own personal health provider. Please always seek a licensed physician in your area regarding all health-related questions and issues.
Sanaz Majd, MD, is a board-certified Family Medicine physician and host of the Majd MD YouTube channel, reviewing the most popular medical topics: www.youtube.com/MajdMD. You can also follow her on Facebook or Instagram: @SMajdMD.
