While discovering new bumps on your skin can be worrisome, the source can be often be identified. New skin bumps may be caused by allergies, injury or infections -- but these type of bumps don't typically appear in a line on the skin. Insect bites, however, are a likely culprit if the bumps show up in a line, curve or a zigzag pattern. Over-the-counter topical medication can usually manage the itch and discomfort associated with bug bites, but you should see a doctor if these bites lead to a severe or allergic response.
Bed bugs are flat, small insects that hide in dark places and usually crawl out to feed during the night. They resemble apple seeds, and are usually 2 to 5 mm in size, according to a January 2013 review in “British Medical Journal.” The bite marks from these blood-feeding insects commonly appear in a line or a zigzag pattern. The first time you suffer from these bites, it may take several days for the itchy welts to appear. According to the American Academy of Dermatology, people become increasingly sensitive to bed bug bites, and with repeated exposure to these bites, symptoms can become more immediate.
Other Potential Culprits
Other insects bites may also cause a line of bumps on the skin. The review in “British Medical Journal” noted that flea bites may appear in a line or a curve, but an October 2012 article in “American Family Physician” outlined that flea bites more commonly show up in an irregular pattern on the skin. The scabies mite also causes raised welts, which could appear S-shaped or in a line, although symptoms can take 2 weeks or longer to appear.
Physiology of Skin Bumps
While there are many causes of new bumps on the skin, the general physiology underlying bump formation is essentially the same. That is, if your skin comes into contact with something it considers foreign, it will release molecules that help to defend your system from this foreign stimulus. This leads to the characteristic red, raised appearance of many bumps on your skin. In the case of insect bites, the body’s reaction to the bites causes the red, itchy bumps.
Treatment of skin bumps depends on the underlying cause. For example, most insect bites resolve in time, and symptoms can be managed by washing with a mild soap and water, and by applying a hydrocortisone or antihistamine ointment or cream. In the case of bed bugs, fleas or scabies, an effective strategy is also needed to prevent ongoing bites. This may involve cleaning clothing and bedding, and hiring a pest control expert. Ask your doctor for guidance on preventing ongoing infestations.
If you have bumps on your skin that bleed, cause ongoing pain or discomfort or don’t go away in a few weeks, see your doctor. Also seek medical attention if you have any signs of an infection, such as a fever, or if your skin bumps are tender, red and oozing pus. Also see a doctor if your skin becomes swollen or if you have hives or a rash that spreads. Seek immediate medical care if you have any signs of a serious allergic reaction, such as difficulty breathing, facial swelling, rapid heartbeat, nausea, dizziness or chest pain.
- British Medical Journal: Bed Bug Infestation
- Centers for Disease Control and Prevention: Joint Statement on Bed Bug Control in the United States from the U.S. Centers for Disease Control and Prevention (CDC) and the U.S. Environmental Protection Agency (EPA)
- American Academy of Dermatology: Bedbugs
- American Academy of Dermatology: Bug Bites and Stings: When to See a Dermatologist
Alex Folkl has been writing for more than eight years and has had work appear in several peer-reviewed and non-peer-reviewed scientific publications. He has a bachelor's degree in biology, a master's degree in pathobiology, and an MD.