Small bumps under your forearms may cause embarrassment and discomfort. A number of conditions, such as an allergic reaction, can cause the skin on your forearms to develop a rash. Aside from an allergic reaction, having small bumps under your forearms could indicate a more serious problem.
Size
Depending upon the cause of the bumps, they may be as small as a pencil eraser or as large as a raisin. The bumps can have a small diameter, similar to the size of a pea, or the diameter can be a couple of inches wide, according to the University of Maryland Medical Center. The bump may appear horizontal or vertical under your forearm.
Features
The bumps may be symmetrical or asymmetrical, according to the American Academy of Family Physicians. The border, or edges, of the bumps may be smooth or irregular. The color of the bumps may vary from pink, red or a reddish-purplish color, or may appear darker such as a light brown or dark black. The tops of the bumps may be round or flat, depending upon the cause.
Causes
Aside from allergic reactions from chemicals, medications or foods, a number of conditions could cause small bumps under your forearms. You may have developed moles or skin tags, or it could be a more serious condition, such as skin cancer. If you are diabetic or your blood sugars are out of control, you may develop small bumps that are diabetic blisters under your forearms, according to the American Diabetes Association. The bumps may also be lichen planus, which can be caused by hepatitis C or certain medications, according to the American Academy of Family Physicians.
Warning
Skin cancer can be fatal, especially when left untreated. Diabetic blisters only appear when your blood sugar is out of control; unstable blood sugar could lead to a diabetic coma or seizure. Hepatitis C is also a very serious condition that can affect other parts of your body. If the bumps are caused by an allergic reaction to a medication, food or chemical reaction and are very severe, you may experience hives all over your body, and the reaction may affect your ability to breathe.
Considerations
If you begin to notice bumps under your forearms, do not wait to have the bumps diagnosed. If the bumps are skin cancer, time is of the essence in regard to treatment. Skin cancer can spread very rapidly. If diabetic blisters cause the bumps, it is imperative to seek immediate medical attention to stabilize blood sugar levels.
