Scarring alopecia, also known as cicatricial alopecia, refers to a
collection of hair loss disorders that may be diagnosed in up to 3% of hair
loss patients. It occurs worldwide in otherwise healthy men and women of all
Each specific diagnosis within this category is fairly rare, but some
examples include dissecting cellulitis, eosinophilic pustular folliculitis,
follicular degeneration syndrome (previously called "hot comb" alopecia),
folliculitis decalvans, lichen planopilaris, and pseudopelade of Brocq, to name
a few. Scarring alopecia may also be part of a much larger condition such as
chronic lupus erythematosus, where many organs of the body can be affected.
While there are many forms of scarring alopecia, the common theme is a
potentially permanent and irreversible destruction of hair follicles and their
replacement with scar tissue.
Most forms of scarring alopecia first occur as small patches of hair loss
that may expand with time. In some cases the hair loss is gradual, without
noticeable symptoms, and may go unnoticed for a long time. In other instances,
the hair loss is associated with severe itching, burning, and pain, and is
The scarring alopecia patches usually look a little different from alopecia
areata in that the edges of the bald patches look more "ragged." The
destruction of the hair follicle occurs below the skin surface so there may not
be much to actually see on the scalp skin surface other than patchy hair loss.
Affected areas may be smooth and clean, or may have redness, scaling, increased
or decreased pigmentation, or may have raised blisters with fluids or pus
coming from the affected area.
These visual indicators may help with diagnosis, but it is difficult to
diagnose a scarring alopecia just from the pattern of the hair loss and the
nature of the scalp skin. Often when scarring alopecia is suspected, one or
more skin biopsies are done to confirm the diagnosis and help identify the
particular form of scarring alopecia. A small biopsy of 2 to 4 mm in diameter
is taken and examined under a microscope. A pathologist or dermatologist will
look for destruction of the hair follicles, scar tissue deep in the skin, and
the presence and location of inflammation in relation to the hair