Page 89 - The Netter Collection of Medical Illustrations - Integumentary System_ Volume 4 ( PDFDrive )

Plate 4-4 Rashes

ACNE KELOIDALIS NUCHAE

Acne keloidalis nuchae is a fairly common form of
inflammatory, scarring alopecia that typically occurs on
the posterior occipital scalp. There is a variable spec-
trum of disease, ranging from very mild cases to severe
scarring alopecia. The condition has psychosocial
implications and is difficult to treat effectively. It is
diagnosed clinically, and biopsies are rarely needed.
Clinical Findings: Acne keloidalis nuchae begins on
the posterior scalp or nape of the neck as tiny, follicular,
flesh-colored to red papules. The papules enlarge Mild. Follicle-centered,
to form plaques, which coalesce into larger plaques. flesh-colored papules
Ultimately in severe cases, the entire posterior scalp
is involved. Early in the disease, no hair loss is appre-
ciated. As the disease progresses, the hair follicles
become scarred down and crowded out by the encroach-
ing fibrosis, resulting in a variable amount of scarring
alopecia.
This condition is far more common in young adult
men, with a predilection for African Americans. It was
originally believed to be caused by close shaving of
the hair and the subsequent inflammation caused by the
newly regrowing hair as it pierces the epidermis. The
curly nature of the hair follicle was believed to be
one of the most important factors. This theory of the
pathophysiology of the disease has been questioned,
and the cause of the condition is not as simple as once
theorized.
The plaques, if left untreated, eventually form thick-
ened scar tissue resembling the appearance of a keloid
scar. The scarring alopecia is permanent, and the
patient is left with a considerable cosmetic issue. Severe
cases of this condition can cause psychological issues,
as can almost any form of severe alopecia.
Pathogenesis: Originally, acne keloidalis was believed
to be caused by the close haircut in African American
men, which caused the hairs to penetrate the epidermis
on regrowth, setting off an inflammatory reaction. It
has now been determined that this is an oversimplifica-
tion of the disease state. Other factors are likely to play
more important roles in the pathogenesis. Severe. The papules of the
Histology: Early disease often appears as a dense, mild form may coalesce
mixed inflammatory infiltrate around the hair follicle into large keloidal plaques
and adnexal structures with plasma cells present. This with associated hair loss.
appears similar to folliculitis. As the hair follicles The areas involved can
rupture, the contents spill into the dermis and set off cause severe disfigurement.
a dermal inflammatory reaction. There is overlying
epidermal hyperplasia and acanthosis. Occasional
pustule formation is seen and is composed of pools of
neutrophils.
Late disease is very similar to the pathology of a
keloid. There is a lack of adnexal structures and fibrosis
throughout the dermis.
Treatment: Therapy for mild disease requires a mul-
tifaceted approach. If only a few papules are present
with minimal hair loss, a combination of a topical and
an oral antibiotic can be used for their antiinflammatory
effects. The most commonly used oral antibiotics are Cutting the hair to a length of 3 to 5 mm is a reasonable Severe disease is rarely responsive to medical therapy.
in the tetracycline class. The topical antibiotic most approach that minimizes trauma to the skin. Topical Surgical options remain the best therapeutic choice.
often prescribed is clindamycin. Strict hair care retinoids such as tretinoin and tazarotene have been The goal is to remove the abnormal skin and close the
regimens are required to help decrease the trauma to used with varying results. The theory is that they help wound under as little tension as possible. If the tension
the skin. Shaving of the scalp should be avoided, and the follicular epithelium mature and help correct the is too great, it is best to leave the wound open to granu-
haircuts with shears should also be minimized, because abnormal keratinization of the epidermis. Intralesional late and heal by secondary intention. The scar that
the shears can cause microtrauma to the skin and poten- triamcinolone injections into the papules and plaques results is often better appearing than the thick, plaque-
tially induce the process and scarring formation. can also be an effective method of treating mild disease. like scar that it is replacing.

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS 75