Page 122 - The Netter Collection of Medical Illustrations - Integumentary System_ Volume 4 ( PDFDrive )

Plate 4-37 Integumentary System

HIDRADENITIS SUPPURATIVA
(ACNE INVERSA) Hidradenitis suppurativa. Abscess, sinus tract
formation, and significant scarring lead to
exquisitely tender areas of involvement. The
axilla, groin, and buttocks are frequently affected.
Hidradenitis suppurativa (acne inversa) is a rare chronic,
life-altering disease. It can be an isolated clinical
finding, or it can be associated with cystic acne, dissect-
ing cellulitis of the scalp, and pilonidal cysts.
Clinical Findings: Hidradenitis suppurativa is most
commonly encountered in postpubertal women. The
ratio of female-to-male involvement is approximately
4 : 1. This condition preferentially affects areas that are
rich in apocrine glands and terminal hairs. The areas
most commonly involved are the axillae, groin, and
inframammary folds. It is rare in other areas. Hidrad-
enitis suppurativa starts as tiny red papules or nodules
that tend to be folliculocentric. The papules are tender
and firm to palpation. At this point, the differential
diagnosis includes an early folliculitis or furunculosis.
As the disease progresses, the hard nodules become Severe
fluctuant and spontaneously drain to the surface of the involvement
skin. The nodules may coalesce into plaques with of the axilla
varying amounts of scarring. The longer the process has
been going on, the more scarring is prevalent. Eventu-
ally, sinus tracts develop that interconnect multiple
subcutaneous nodules with multiple cutaneous open-
ings. Clinically, pressing on one of the nodules may
produce drainage from a distant sinus tract. The disease
is relentless, and new crops of lesions repeatedly
develop. Pain is significant and is a main cause of mor-
bidity. Obesity tends to be seen in association with
hidradenitis suppurativa. Hidradenitis has been seen in
association with Crohn’s disease, and some believe that
hidradenitis suppurativa is a cutaneous form of Crohn’s
disease. Long-standing disease has been associated with
the development of squamous cell carcinoma. The
tumors tend to be large at diagnosis
The drainage from the cutaneous nodules often
requires extensive bandaging to keep clothing from
getting soiled. The drainage has a malodorous, foul
smell. The draining sinus tracts and nodules are often
colonized with various bacteria, and cultures of the puru-
lent drainage show growth of a number of different
organisms, including Staphylococcus aureus and strepto-
coccal species. However, this is not primarily an infec-
tious disease. The bacteria in these cases are present
secondary to the underlying inflammatory condition
and the lack of normal cutaneous skin barrier function.
Pathogenesis: Hidradenitis suppurativa is an inflam-
matory disease with secondary bacterial superinfection
and colonization. Routine culturing of the nodules and
the drainage is often sterile. Hidradenitis is theorized
to be caused by rupture of the mature follicular epithe-
lium along areas of apocrine glands; hence, its propen-
sity to occur in areas with high densities of apocrine
glands. A hormonal control over the process has been
theorized, given that it is more common in postpubertal Hidradenitis suppurativa (acne inversa)
women and in obese individuals. Once the hair follicle on the groin
ruptures, an inflammatory cascade is set off and causes Severe inflammatory hidradenitis suppurativa of the buttocks
the resulting nodules, cysts, fistulas, and scarring. It
appears to be a self-perpetuating process. The exact
mechanism by which this occurs is unknown.
Histology: Chronic lesions show a dense, mixed anecdotal reports of success. Topical clindamycin and affected tissue and repair with complex flap closure.
inflammatory infiltrate with abscess and sinus tract for- other antibacterial products such as benzyl peroxide are Liposuction has also been tried in an attempt to remove
mation. Varying amounts of fibrosis and scar tissue are often the first-line agents employed for mild disease. the affected apocrine gland hair follicle unit. The only
present. Apocrine gland inflammation can be appreci- Oral antibiotics, typically in the tetracycline class, are potential for cure is with a surgical approach. This
ated in a fair number of cases. The inflammation often used because they have both antiinflammatory approach seems to work best for axillary disease; groin
extends into the subcutaneous tissue. and antibacterial properties. Weight loss must be advo- and inframammary disease almost always recurs after
Treatment: Therapy is often aimed at reducing cated. Other agents that have had limited success surgery. It is also of the utmost importance to address
inflammation and bacterial superinfection. There is no include isotretinoin, etanercept, and infliximab. Surgi- patients’ psychosocial needs, because this disease has a
curative therapy, and most treatments have only cal options include wide local excisions to remove the devastating toll on the patients it afflicts.

108 THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS