Chemically damaged hair

Question
About four years ago, i let my licensed beautician put permanent color in my hair.  She put me under the dryer and left me there for almost an hour.  A couple of weeks later my hair started coming out by the handful.  If i rubbed my head, my hand was full of hair.  My hair was messed up.  It was short and long in different places all over my head.  Since i had long hair and couldn't bear to part with it, i trimmed it often and started doing it myself.  The problem  is, it grows but it has thinned out.  My hair was twice as thick as it is now.  What kind of damage did the permanent color do?  Why want it grow back thick?


Answer
This is a relatively common problem dermatologists deal with. If left on too long the chemicals damage the hair shaft where the liquid sits on top of the scalp. By the time the person notices excessive hair loss the hairs have grown for a week or two and are breaking off 1/4 inch above the scalp. The scalp itself is rarely irritated enough to have anything more than a mild contact dermatitis which is not severe enough to injure the hair follicles or hair roots. Typically over a six month period the hairs continue to break off and are now leaving about a 3 inch hair shaft behind because the hairs grow 1/2 inch per month. It will take two years from the time of the injury to the hair shafts for the hair to grow to be 12 inches long. By this time most patients are frustrated the hairs are of different lengths as you were. Other factors may be involved in why there was so much hair loss and why much of it did not grow back. Some other stressful factors could have caused you to have a "Chronic Telogen Effluvium" and poor regrowth of those lost hairs may be due to not having enough serum ferritin ( low iron ). Seeing a dermatologist may help determine if there was scarring of the hair follicles which is normally not a problem with hair coloring but is a problem with "Hot Comb" straightening of the hair. There could be several different factors going on here and by looking at your scalp your dermatologist will be able to give you the best advice as to what treatment is liable to help and the amount of hair to expect to grow back.