Tiny rough bumps on my arms
You run your hand down the back of your arm. The skin feels like fine sandpaper. The bumps may look red, brown, gray, or the same shade as the rest of your skin.
Most of the time this is keratosis pilaris. It is very common and it is not catching. Many people first notice it as a child or teen.
The bumps sit on the back of the upper arms most of all. They can also show up on the thighs, the butt, and the cheeks. The skin may feel rough all year, or only in cold months.
When to see someone
Go to urgent care if the skin turns hot, red, and puffy and spreads fast. That can mean an infection under the skin. Go the same day if you also feel feverish.
See a doctor soon if bumps leak pus or hurt to touch. That points to infected hair roots, not rough skin. It may need a cream or pills from a doctor.
Book a visit if the itch keeps you up at night. Also book one if the rash is new to you as an adult. New rashes in adults can have other causes.
Call your doctor if an acid or retinol leaves your skin raw, burning, or weepy. Stop the product first.
Get help right away if your lips, face, or throat swell. The same goes if you feel short of breath. Call 911 or your local emergency number.
Why it happens
Each bump sits where a hair comes out of the skin. Keratin is a tough protein that your skin makes. When too much of it builds up, it plugs the tiny opening.
The plug traps the hair under it. That forms a small, hard bump you can feel. Some plugs trap a curled hair, which can look like a dark dot.
This trait often runs in families. Dry, cold air makes it worse, since dry skin sheds cells more slowly. It is not caused by poor washing, and scrubbing will not fix it.
What else it could be
Rough arm bumps have more than one cause. The right care depends on which one you have.
Keratosis pilaris feels like grit or sandpaper. It sits on the back of the upper arms, the thighs, or the cheeks. It rarely itches much, and it has often been there for years.
Dry skin and eczema itch a lot. The skin looks flaky or cracked, not like fine grit. Eczema can weep clear fluid and comes in flares.
Folliculitis means sore or infected hair roots. The bumps have white or yellow tips and hurt when you press them. It often starts a few days after shaving, waxing, or a hot tub.
Heat rash shows up after you sweat. The bumps sting or prickle. They fade in a few days once your skin cools.
Hives are raised welts that itch hard. They move to new spots and fade within a day. A new soap or lotion can also leave an itchy red patch right where it touched.
One more clue: a rash that came on fast, in days or weeks, is not keratosis pilaris. That kind needs a doctor to name it.
How to read the grades below
The options below come from our page on Keratosis Pilaris. Each one carries two labels.
The first label is the evidence grade. A means strong trials in people, B means smaller or mixed studies, and C means early or limited findings. D means lab work only, and “insufficient” means the research cannot settle it yet.
The second label is the traditional tier. T3 means long use in more than one tradition, T2 means long use in one, and T1 means known use. T0 means no such record.
These grades come from research on Keratosis Pilaris, the parent Health Topic, not on tiny rough bumps on my arms.
A grade tells you how strong the research is, not how well something will work for you. Talk to a doctor or pharmacist before you start anything, above all if you take other medicines.
What to try first
Start gentle. Warm water rather than hot is worth trying. Pat dry and put cream on while the skin is still damp.
Do not pick or scrub hard. Picking leaves dark or red marks that last months.
Next, pick one acid that loosens the plugs. Lactic Acid Topical has an evidence grade of A. Glycolic Acid (Sugar Cane) also has an evidence grade of A.
Salicylic Acid (Willow Bark) has an evidence grade of B. It comes from willow, so its traditional tier is T3. Any of these three can work; use just one at a time.
Some people start the acid at night, every other night at first, and see how their skin takes it. Move to daily if your skin stays calm. Stop for a few days if it stings or peels.
Retinol (Vitamin A Topical) has an evidence grade of A. It helps skin shed old cells. Start with two nights a week, and do not use it on the same night as an acid.
For plain moisture, Shea Butter has an evidence grade of C and a traditional tier of T2. Coconut Oil has an evidence grade of insufficient and a traditional tier of T3. That means folk use is long, but study proof is thin.
Dry Brushing has an evidence grade of D and a traditional tier of T1. Proof is weak. Brushing hard can leave the skin redder than before.
Skip retinol and acids if you are pregnant or nursing, unless your doctor says yes. Wear sunscreen on bare arms while you use them.
How long it takes
Skin is slow to change. Give any one thing at least four to six weeks of steady use. Many people feel the rough patch soften before they see it fade.
Redness takes longer than roughness. Dark or red marks can take months to fade on their own. No product can promise that the bumps will clear.
The bumps often come back if you stop. Many people keep using a cream a few nights a week to hold their gains. It is also normal for the skin to get rough again each winter.
