Found this information on why curly hair can result in ingrown hairs--
Extrafollicuar Penetration
The conditions for ingrown hair begin with the presence of curved hair follicles in your skin, MayoClinic.com reports. Hairs produced by these types of follicles tend to be tightly curled.
When you shave this curly hair, you give it a sharpened edge that allows it to reemerge from your follicles and penetrate your skin, leading to ingrown hair and its related symptoms. This process is known as extrafollicular penetration. Shaving your hair without water or lubrication can encourage the formation of the sharpened hair edges associated with ingrown hair.
Transfollicular Penetration
If you keep your skin taut while you shave, your cut hair can pull back into your follicles, MayoClinic.com notes. When it grows out, this hair can directly penetrate your skin without ever reaching the surface. This process is called transfollicular penetration. You
can also develop ingrown hair if you don't hold your skin taut but use a double-edged razor, which pulls your hair out and then allows it to retract below the surface of your skin. If you use tweezers to remove hair, you can develop transfollicular penetration when hair fragments are left in your follicles.
Symptoms
When ingrown hair penetrates your skin, your body treats it like a foreign intruder. Common symptoms of this reaction include skin inflammation and pus formation, according to Brigham and Women's Hospital. MayoClinic.com lists additional symptoms that include pain, itching, unusual darkening of your skin and the formation of small, round bumps.
Treatment
If you have razor bumps, you can eliminate them by letting your hair grow out for roughly one month, according to the New Zealand Dermatological Society. Once you begin shaving again, use a single-edged razor or an electric razor that leaves your hair a little longer. You can also help avoid razor bumps by shaving in the same direction that your follicles naturally grow. If you tweeze or wax your hair, you can also avoid ingrown hair by stopping these procedures, MayoClinic.com notes. If necessary, you can remove unwanted hair through laser hair removal, which does not promote ingrown hair formation.
Read more:
http://www.livestrong.com/article/257759-cause-of-ingrown-hair/#ixzz16mlNdBlA