Black Dots: Hair dye as an example

Hair dye as an example

Magnified and dermatoscopic images of the scalp have an important role in making proper diagnoses. Black dots (as shown here) are a dermatosocpic sign that is encountered from time to time.

There are many causes of black dots that must be considered. Black dots are seen in alopecia areata, tinea capitis, traction alopecia and rarely some scarring alopecias too. Other causes are possible too and this list is not complete. Black dots generally represent hair follicles that have broken off at the level of the scalp. Black dots can also be caused by a variety of different “dyes” that dye the hair follicle opening and therefore do not actually represent broken hairs.

In this photo, the black dot represent recent use of hair dye that has colored the hair follicle opening or “pore.” Other types of dyes, such as anthralin used in alopecia areata treatment, also color the opening.