Cellulitis - Anogenital in
See also in: Overview,Cellulitis DDx,Hair and Scalp,Oral Mucosal LesionAlerts and Notices
Synopsis
- Immunocompetent adults: common etiologies include Staphylococcus aureus (particularly if there is concurrent purulence) and Streptococcus pyogenes.
- Immunocompromised individuals: common pathogens such as S aureus and Streptococcus should be considered, but gram-negative pathogens should also be considered and covered.
- Diabetic foot infections and decubitus ulcers: consider a mixture of gram-positive cocci and gram-negative aerobes and anaerobes.
- Aquatic soft tissue injury: Vibrio spp, Aeromonas spp, Mycobacterium marinum, etc.
Risk factors for developing cellulitis include minor skin trauma, atopic dermatitis, contact dermatitis, body piercings, intravenous (IV) drug use, tinea pedis infection, animal bites, peripheral vascular disease, obesity, older age, immune suppression (chronic systemic steroid use, neutropenia, immunosuppressive medications, organ transplantation, HIV), and lymphatic damage (lymph node dissection, radiation therapy, vein harvest for coronary artery bypass surgery / saphenous venectomy, and damage that occurs following multiple prior episodes of cellulitis).
Fevers, chills, and malaise may precede the onset of cellulitis but may also be absent. Poorly defined borders, erythema, swelling, tenderness, and warmth characterize typical cellulitis lesions. In adults, the extremities, particularly the lower extremities, are the most common sites affected. In more severe cases, additional clinical features may include vesicle and bullae formation, pustules, and necrosis. Complications are not common but can include glomerulonephritis, lymphadenitis, and bacteremia.
A rising prevalence of MRSA has been identified as a pathogen of skin and soft tissue infections in otherwise healthy individuals lacking the aforementioned risk factors for cellulitis. MRSA should be considered for penetrating traumas, purulent infections, and in specific populations: athletes, children, prisoners, military service members, long-term care residents, and IV drug users. Other MRSA risk factors include recent admission to a health care facility, presence of an indwelling catheter, poor personal hygiene, and history of MRSA.
Recurrent Cellulitis: Major risk factors for recurrent cellulitis include chronic edema, dermatomycosis, and lymphatic or venous insufficiency. Prior episodes of cellulitis, immunodeficient states, obesity, previous local surgery / saphenectomy, as well as having cancer, can also increase the risk of recurrent cellulitis.
In all, the majority of cases of cellulitis resolve with appropriate antibiotic therapy. The decision to hospitalize a patient presenting with cellulitis will depend on the clinical picture and the patient's medical comorbidities. For any case of genital cellulitis, it is important to exclude Fournier gangrene.
Codes
ICD10CM:L03.90 – Cellulitis, unspecified
SNOMEDCT:
128045006 – Cellulitis
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Differential Diagnosis & Pitfalls
- Contact dermatitis
- Epididymo-orchitis
- Testicular torsion
- Herpes virus infections (herpes simplex virus or zoster with associated lymphangitic erythema)
- Fournier gangrene
- Gas gangrene
- Abscess (pilonidal or other)
- Hematocele
- Incarcerated or strangulated hernia (see inguinal hernia)
- Fixed drug eruption
- Pyoderma gangrenosum
- Calciphylaxis
- Lymphedema
- Lymphogranuloma venereum
- Granuloma inguinale
- Genitourinary Crohn disease
- Intertrigo
- Erythrasma
- Tinea cruris
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Therapy
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References
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Last Reviewed:03/14/2023
Last Updated:04/02/2023
Last Updated:04/02/2023
Patient Information for Cellulitis - Anogenital in
Overview
Cellulitis is an infection of the skin that is most often caused by the bacteria Staphylococcus ("staph") and Streptococcus ("strep"). These bacteria are able to enter the skin through small cracks (fissures), causing sudden redness, swelling, and warmth in an area of the skin. Cellulitis is sometimes accompanied by fever, chills, and feeling fatigued.If the infection is left untreated for too long, cellulitis can result in abscesses (swollen, warm, tender lumps filled with pus) or the spread of bacteria into the bloodstream (bacteremia). However, most cases of cellulitis resolve with appropriate antibiotic therapy.
Who’s At Risk
Cellulitis can occur in anyone or any age, race / ethnicity, and sex. Factors that increase the risk of developing cellulitis include:- Diabetes.
- Lymphedema.
- Skin wounds.
- Chronic lower leg swelling (edema).
- Athlete's foot (tinea pedis).
- Bites from insects, animals, or other humans.
- Obesity.
- Poor circulation in the legs (peripheral vascular disease).
- Weakened immune system due to underlying illness or medication.
- Intravenous drug abuse.
Signs & Symptoms
Cellulitis can affect any part of the body, but the most common locations are the:- Lower legs.
- Arms or hands.
- Face.
Cellulitis may be accompanied by swollen lymph nodes, fever, chills, and fatigue.
Self-Care Guidelines
If you think you have cellulitis, make an appointment to see your medical professional. While you are waiting for the appointment, elevating the involved body part, if you are able, can help decrease swelling. A cool, clean, moist towel can be applied to the area to decrease pain.When to Seek Medical Care
If you develop a painful, warm, enlarging area on your skin that is red or a darker color than your surrounding skin, make an appointment with your medical professional as soon as possible to get treatment and to avoid complications that may occur if cellulitis is left untreated. If you also have fever and chills or if the area involves the face, you should go to urgent care or the emergency room.If you are currently being treated for a skin infection that has not improved after 2-3 days of antibiotics, return to your medical professional. You may need treatment with different medications, or the infection may have spread deeper into your skin.
Treatments
Your medical professional will usually be able to easily diagnose cellulitis by examining the affected area. Sometimes they may want to get additional information by ordering blood tests and/or performing a bacterial culture to identify the specific bacterium that is causing the cellulitis as well as to test its susceptibility to different antibiotics, which helps guide treatment decisions.While waiting for the results from the bacterial culture, your medical professional may want to start you on an antibiotic to fight the most common bacteria that cause cellulitis. Once the final culture results have returned, your medical professional may change the antibiotic you are taking, especially if your infection is not improving.
Mild cases of cellulitis in a healthy person can be treated with oral antibiotics. Common antibiotics that are used to treat cellulitis include:
- Trimethoprim-sulfamethoxazole (eg, Bactrim).
- Doxycycline (eg, Vibramycin).
- Minocycline (eg, CoreMino).
- Clindamycin (eg, Cleocin).
- Dicloxacillin.
- Cephalexin (eg, Keflex).
- Linezolid (eg, Zyvox).
- Vancomycin (eg, Firvanq, Vancocin).
- Linezolid.
- Cefazolin (eg, Claforan).
- Oxacillin.
- Nafcillin.
- Clindamycin.