ABSCESS Flashcards
A well-circumscribed, painful, inflammatory nodule at any site that
contains hair follicles. May extend into the dermis and subcutaneous tissues.
Furuncle (AKA boil)
A collection of pus within the dermis and deeper skin tissues. Manifests as
painful, tender, fluctuant, and erythematous nodules.
(1) Typically do not present with systemic symptoms.
Skin abscess:
A coalescence of several inflamed follicles into a single inflammatory mass
with purulent drainage from multiple follicles.
(1) Typically presents with systemic symptoms and fever
Carbuncle:
Etiology & Pathophysiology
(1) Infection spreads away from hair follicle into surrounding dermis.
(2) Pathogenic strain of S. aureus or CA-MRSA.
Risk factors
(1) Carriage of pathogenic Staphylococcus sp. in nares, skin, axilla, and perineum
(2) Diabetes mellitus, malnutrition, alcoholism, obesity, atopic dermatitis
(1) Deep subcutaneous erythematous papules enlarge to deep-seated nodules that can be
stable or become fluctuant within several days.
(2) Most commonly occurs on the back of the neck, upper back and the lateral thighs.
(3) Tender, perifollicular swelling, terminating in discharge of pus & necrotic plug.
(4) malaise, chills and fever may precede or occur during the height of
inflammation.
Carbuncle
Incision and Drainage/Treatment is the mainstay of treatment for an abscess, furuncle, or
carbuncle.
Carbuncles should be handled by dermatology or general surgery in all situations
unless patient is unable to be transferred.
Systemic antibiotic therapy for extensive cases
(a) MSSA
1) Dicloxacillin 250-500 mg QID for 10 days
2) Cephalexin 250-500 mg QID for 10 days
3) Amoxicillin and Clavulanate (Augmentin) 875 mg BID for 10 days
(b) MRSA
1) Doxycycline 100 mg BID
2) Trimethoprim-Sulfamethoxazole DS BID
3) Clindamycin 150-300 mg BID for 10 days
Differential Diagnosis
(1) Ruptured Epidermal cyst
(2) Atypical Abscess
(3) Furuncle = Carbuncle
(4) Carbuncle = Furuncle
Labs/Studies/Imaging
(1) CBC is indicated if patient has fever or signs/symptoms of systemic disease
Disposition
(1) Duty status based on location, severity and control of infection.
(2) Wound should be checked throughout treatment to ensure symptom improvement and
adequate drainage/healing
(1) Cysts, or, improperly sebaceous cysts) are the most common benign cutaneous cysts.
(2) Can occur anywhere on the body and the size ranges from a few millimeters to several
centimeters in diameter.
(3) The cyst wall consists of normal stratified squamous epithelium derived from the
follicular infundibulum.
(4) Cyst may be primary (de novo) or may arise from the implantation of the follicular
epithelium in the dermis as a result of trauma or from a comedone.
(5) Lesions may remain stable or progressively enlarge.
(6) Spontaneous inflammation and rupture can occur, with significant involvement of
surrounding tissue.
Epidermal Cysts
(1) Usually a firm or fluctuant flesh-to-yellow colored solitary nodule (0.5 to 5 cm) which
often connects with the surface by keratin-filled pores.
(2) Cyst grow slowly over time and may remain stable for months or years.
(3) Commonly located on face, neck, upper back, chest; if due to trauma, on buttocks,
palms, or plantar side of feet.
Stable Epidermal Cyst
(1) Inflamed epidermal cysts are warm, red and boggy and tender on palpation.
(2) Sterile, purulent material and keratin debris often point towards and drain to the
surface.
(3) These lesions mimic and present very similarly to abscesses.
(4) There is no way to predict which lesions will remain quiescent and which will become
larger or inflamed
Inflamed/Ruptured Epidermal Cyst
Differential Diagnosis
(1) Lipoma
(2) Other benign and malignant tumors:
(a) Dermoid cyst
(b) Furuncle
(c) Milia
