eMedicine Case Study
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Recurrent Painful and Purulent Lesions of the Groin
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Hidradenitis suppurativa (HS): The image shows tender, inflamed papules and nodules, with active
drainage of purulent material. The patient’s CBC revealed underlying anemia associated with her chronic
disease. Regional lymphadenopathy was typically absent, and the characteristically foul odor of chronic
HS was noted.
HS is a disorder of the terminal follicular epithelium in apocrine gland–bearing skin. It most commonly
occurs in regions rich in apocrine glands, such as the axilla, the groin, the perineum, and the perianal
region. The condition can also occur on the buttocks, the scrotum, and the submammary areas. HS in
the perineal region tends to be the most severe. The onset of disease is often correlated with the
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development of apocrine sweat glands after puberty (most frequently in the second and third decades of
life). HS is thought to affect 1% of the population worldwide, and it most often affects women, with a
female-to-male ratio of 2-5:1.
HS is believed to start with the formation of keratin comedones in the apocrine-gland follicles. This leads
to occlusion of the apocrine ducts with subsequent superimposed inflammation and infection.
Abscesses eventually form, with chronic infection that spreads in the area of involvement, induration,
and sinus tract and fistula formation. Episodes of acute cellulitis are a common complication of HS. The
early lesions of HS are isolated pruritic nodules that may be painful and may persist for weeks or
months without change. The nodules typically develop into pustules that eventually rupture, draining
blood-stained, purulent material. Recurrences then develop at the original site. The severity and natural
course of the condition vary from patient to patient, but untreated HS is typically a relentless, progressive
disease. Acute exacerbations and remissions are characteristic, often leading to sinus-tract formation
with marked scarring.
The cause of HS is unknown, though current theories suggest a multifactorial etiology. Conditions that
may contribute to the development of HS include genetic predisposition, obesity, and local frictional
trauma. Local folliculitis or previous episodes of skin infection with organisms such as streptococci,
staphylococci, and Escherichia coli may also be part of the etiology of HS. Hormonal factors, such as
low levels of estrogen and/or high levels of androgens, are also thought to predispose patients to HS;
this accounts for the increased incidence or severity of HS with pregnancy and oral contraceptive use.
Poor hygiene does not cause HS, and the disease is not contagious.
HS is clinically recognized to have 3 stages of progression, which dictate therapeutic intervention. Stage
1 is characterized by single or multiple abscesses without sinus tracts or scarring. Stage 2 is
characterized by recurrent abscesses with sinus-tract formation and scarring. Finally, diffuse or broad
involvement with multiple interconnected sinus tracts and abscesses characterize stage 3.
Nonspecific therapeutic measures for all patients with HS include good hygiene, weight reduction, use of
antiseptic detergents, and avoidance of tight-fitting clothes. Acute-stage treatments include a 2-week
course of antibiotics that may include a combination of erythromycin and metronidazole, minocycline, or
clindamycin. In addition, intralesional steroid injections may cause early lesions to involute within 12-24
hours of injection. For patients with chronic relapsing disease, treatment options include long-term
antibiotics, high-dose systemic steroids, estrogens, and retinoids. Stage 2 or 3 disease with chronic
sinus tracts may be treated with total wide excision and healing with flaps and/or grafts.
This patient was initially treated with topical silver sulfadiazine (Silvadene) and systemic
amoxicillin/clavulanate potassium (Augmentin). With this therapy, the patient’s associated cellulitis
markedly improved, and the chronic inflammation that had characterized her condition partially resolved.
After the acute exacerbation subsided, she was noted to have chronic draining fistulas and established
abscesses. She was referred to a plastic surgeon, who surgically resected the involved areas in the
groin and perineum. Advancement skin flaps were used to close the defect primarily, with drains left in
the subcutaneous tissue plane for 5 days. The patient healed uneventfully and returned to work within 2
weeks. At the time this case study was written, the patient had not experienced any additional episodes
of active HS since her surgery.
For more information on HS, see the eMedicine articles
(in the Dermatology
(in the General Surgery section), and
1 American Academy of Family Physicians. Information from your family doctor. Hidradenitis
2 Babcock MD, Grekin RC. Antibiotic use in dermatologic surgery. Dermatol Clin. 2003
3 Fite D. Hydradenitis suppurativa. eMedicine Journal [serial online]. Last updated: May 22, 2006.
4 Jovanovic M, Kihiczak G. Hydradenitis suppurativa. eMedicine Journal [serial online]. Last
5 Kagan RJ, Yakuboff KP, Warner P, Warden GD. Surgical treatment of hidradenitis suppurativa: a
6 Lebwohl B, Sapadin AN. Infliximab for the treatment of hidradenitis suppurativa. J Am Acad
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7 Naveen P, Kiran RP. Hydradenitis suppurativa. eMedicine Journal [serial online]. Last updated:
8 Shah N. Hidradenitis suppurativa: a treatment challenge. Am Fam Physician. 2005 Oct
A 47-year-old woman presents to her primary care physician with a history of several years of chronic
skin infections and painful, 1-3 mm red pustules in her groin area. Many of the pustules have broken and
are draining a foul-smelling, puslike fluid mixed with what appears to be blood. The patient reports that
these lesions almost always begin as firm bumps that are not painful and then eventually break open.
Additionally, the patient has had episodic abscess formation in the involved area for many years, with
extreme discomfort for at least the past 18 months.
The patient has seen physicians for this problem in the past and has been treated with oral and topical
antibiotics. The nodules seemed to improve when she was taking the antibiotics, but nothing has
stopped the recurrences or cured the condition. Any contact with the affected area increases the irritation
and pain. The patient has felt socially uncomfortable because of the strong, offensive smell, and her
pain has caused her to substantially reduce her activity level.
The patient’s medical history is significant for morbid obesity, which led her to undergo gastric bypass
surgery. The inflammation and pain in her groin worsened after she lost over 100 lb. Now, many of the
eruptions occur in the fold under her pannus. She reports no fever and no exposure to new chemical
agents, detergents, or cleaning agents.
On physical examination, her vital signs are a temperature of 98.6°F (37.0°C), a heart rate of 88 bpm,
and a blood pressure of 132/65 mm Hg. The patient has a nontoxic appearance, and the cardiovascular
examination findings are normal. There is no clinically significant lymphadenopathy, even in the inguinal
area and in the armpits. She has numerous draining lesions in various stages of eruption; those in the
groin and perineal regions are tender to palpation. Evidence of coalescence of some of the lesions and
a spreading redness in the inguinal area are observed.
The patient’s complete blood count (CBC) shows the following values: white blood cell (WBC) count, 8.6
/L; hemoglobin (Hb), 8 g/L; hematocrit (Hct), 0.259 (25.9%); and platelets, 361 × 10
The nodules are recurrent, are painful,
and are discharging fluid.
Medicine Residency, Westchester Medical
Center, New York Medical College, Valhalla,
Jane A. Petro, MD, Chief of Plastic Surgery,
Surgery, New York Medical College, Valhalla,
Professor, Yale School of Medicine, Section
of Emergency Medicine, Department of
Surgery, Attending Physician, Medical
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