Skin Disorders
Bookmark and Share
   Acquired Melanocytic Nevocellular Nevi
   Acral Lentiginous Melanoma
   Acute HIV Syndrome
   Acute Lymphangitis
   Acute Sun Damage
   Adult T Cell Leukemia
   Adverse Cutaneous Drug Reactions
   Alopecia Areata
   Androgenetic Alopecia
   Aphthous Ulcer
   Bacillary Angiomatosis
   Bacterial Infections
   Basal Cell Carcinoma
   Basal Cell Nevus Syndrome
   Behcet's Syndrome
   Benign Cutaneous Neoplasms
   Capillary Hemangioma of Infancy
   Cat-Scratch Disease
   Chronic Lupus Panniculitis
   Chronic Venous Insufficiency
   Clark Melanocytic Nevus
   Congenital Nevomelanocytic Nevus
   Crest Syndrome
   Cutaneous Candidiasis
   Cutaneous Larva Migrans
   Cutaneous Lupus Erythematosus
   Cutaneous and Mucocutaneous Leishmaniasis
   Cutaneous Pseudomonas Aeruginosa Infections
   Cutaneous Reactions to Arthropod Bites
   Cutaneous T Cell Lymphoma
   Desmoplastic Melanoma
   Disseminated Coccidioidomycosis
   Disseminated Cryptococcosis
   Disseminated Gonococcal Infection
   Disseminated Intravascular Coagulation
   Drug Hypersensitivity Syndrome
   Drug-Induced Acute Urticaria
   Drug-Induced Pigmentation
   Eosinophilic Folliculitis
   Erysipelas and Cellulitis
   Erythema Infectiosum
   Erythropoietic Protoporphyria
   Exanthematous Drug Reactions
   Exfoliative Erythroderma Syndrome
   Extramammary Paget's Disease
   Eye Stye
   Fixed Drug Eruption
   Gangrenous Cellulitis
   Genital Candidiasis
   Giant Cell Arteritis
   Glucagonoma Syndrome
   Graft Versus Host Disease
   Hand-Foot-and-Mouth Disease
   Herpes Gestationis
   Herpes Simplex Virus: Genital Infections
   Herpes Simplex Virus Infection
   Herpes Simplex Virus: Infections Associated Systemic Immunocompromise
   Herpes Simplex Virus
   Herpes Zoster
   HIV Associated Lipodystrophy Syndrome
   Human Papillomavirus: Mucosal Infections
   Human Papillomavirus: Squamous Cell Carcinoma In Situ
   Human Papillomavirus
   Hypersensitivity Vasculitis
   Hypertrophic Scars and Keloid
   Impetigo and Ecthyma
   Infectious Exanthems
   Infectious Folliculitis
   Infective Endocarditis
   Infestations of the Skin
   Kaposi's Sarcoma
   Kawasaki's Disease

Bacterial Infections


Invasion of the skin, its appendages, and/or subcutaneous layer by way of thermal, mechanical, chemical, or physiologic injury and the colonization or infection with pathogenic bacteria of both aerobe and anaerobic nature. Lesions are usually due to immune system response and purulence is present.

Classified as follows: Boils and abscesses: Localized-isolated skin soft tissue collections of infection.

Furuncles, carbuncles: Local infections of hair follicles single and multiple respectively.

Folliculitis: Local or widespread areas of multiple small distal infections of pilosebaceous units.

Impetigo: Superficial epidermal infection (Staphylococcus aureus and Streptococcus pyogenes are the most common skin pathogens). Ecthyma: Deep epidermal and high dermal infection with same staphylococcal streptococcal bacteria.

Erysipelas, cellulitis: Infection of deep skin layers into subcutaneous layer; widespread and diffuse.


Symptoms Boils and abscesses: Small and large, localized, tender, painful, red, and inflamed.

Furuncles, carbuncles: Single or several single in confluent group of red papules, wann and tender.

Impetigo: Weepy, crusty sores, single or multiple, small and large. Some tenderness, rare fever.

Ecthyma: Large weepy crusty almost ulcerative sores; occasional fever and tenderness.

Erysipelas, cellulitis: Red, warm, swollen, tender, and painful skin areas. Fevers common. Eye may be swollen closed.

General: Investigate environmental exposures or known contacts for skin injury and bacterial proximity.


Boils, abscesses: Any, but usually more prevalent post pubescent.

Furuncles,carbuncles: Any, but more common in teens and adults.

Folliculitis: Any.

Impetigo: Any, but more common in children.

Ecthyma: Any.

Erysipelas, cellulitis: Any, but usually in the adult.


Boils, abscesses: Suddenly, with small surface papule or deeper indurated small nodule.

Furuncles, carbuncles: Sudden with chronic spread possible from single to several lesions.

Folliculitis: Sudden with few to many lesions, to chronic beginning few local to widespread many areas.

Impetigo: Sudden with one or more papules.

Ecthyma: Sudden with one or more lesions.

Erysipelas, cellulitis: Sudden but insidious.


Boils, abscesses: Days, weeks, or months until treated.

Furuncles, carbuncles: Days, weeks, or months until treated.

Folliculitis: Weeks, months, or years until treated. Impetigo: Weeks or months unless treated.

Ecthyma: Weeks or months .

Erysipelas, cellulitis: Weeks, and can have serious complications if untreated.

Intensity Boils, abscesses: Single to few, almost asymptomatic to widespread with systemic signs (e.g., fever, listlessness).

Furuncles, carbuncles: Few local to many widespread with only minimal systemic potential.

Folliculitis: Small, local to extensive widespread. Rare systemic effect.

Impetigo: Single to multiple and widespread lesions with systemic effect possible in extensive disease.

Ecthyma: Single to multiple and widespread lesions with systemic effect possible in extensive disease.

Erysipelas, cellulitis: Mild to extensive local lesions with mild to severe systemic signs common.

Aggravating Factors: Further or continued exposure to skin traumatizers, lack of treatment, uncleanliness, poor hygiene, immune deficiency.

Alleviating Factors: Meticulous, gentle skin cleansing especially with antibacterials, strong efficient immune system.

Associated Factors: Environmental exposure.

Physical Examination

General: The patient usually appears in no acute distress. Obtain temperature and vital signs to evaluate for the possibility of sepsis.


Boils and abscesses: Papular or nodular soft tissue indurations with inflammation and tenderness. Abscesses will be fluctuant at some time in their course and may exhibit a point with a purulent top. May be in any soft tissue location, but most common in the axillae, groin, and high inner thighs. Any skin gland, node, or opening can develop an abscess.

Furuncles, carbuncles: Found everywhere there are sweat or oil ducts, but most common upper back, chest, neck, axillae, and groin. Inflammed, single pustules seen with furuncles and groups of small neighboring pustules in single inflammed lesion seen with carbuncles. Carbuncles may be quite tender.

Folliculitis: Single, red papules and/or pustules scattered diffusely and widely over the body anywhere there are hair follicles. May be seen in smaller local groups or patches (e.g., the whisker area, buttocks, or chest). Usually no surrounding erythema or inflammation.

Impetigo: Small red papules, vesicles, or pustules seen initially. May develop into roundish, broad, superficial, crusted weepy erosions. Thick-piled crusts of honey-brown are generally due to Streptococcus and thin smooth crusts due to Staphylococcus. Lesions may be solitary or multiple and exist in a wide area or grouped closely. Generally on the face of children, but may affect any location.

Ecthyma: Slightly inflammed deeper erosions with moist or dry crustingin concentric lesions of skin. May occur in any location, usually on smooth skin.

Erysipelas, cellulitis: Local marked erythematous swellings with discreet, raised border and mild honey weep. Seen on dry warm surface of facial areas (e.g., ear, cheeks, nose, periorbital area in adults). Local large or small erythematous warm, tender, irregularly bordered swellings of skin and soft tissues in any area of the child or adult. Often associated with fever and listlessness. May have moist serous ooze on surface with cellulitis.

Lymphatic: All of the bacterial skin infections may cause local or regional lymph node swelling and tenderness.


S. pyogenes, and S. aureus (nonresident flora) are the most common bacterial skin pathogens although sometimes caused by resident bacteria as diphtheroids and coagulase negative staphylococci. Haemophilus injfuenzae may be the cause of childhood facial cellulitis.

Pseudomonas aeruginosa is encountered in some whirlpool, hot tub, swimming pool folliculitis. S. epidermidis may be the causative agent in some body abscesses.

Occasional anaerobes of abscesses are peptococci, and propionibacterium species. Perineal, genital, buttock abscesses often contain fecal bacteria (e.g., alpha and nonhemolytic streptococcus, anaerobic gram-positive cocci, and bacteroides species).

Diagnostic Studies

Usually none needed but on occasion used to differentiate pathogen especially if systemic signs and symptoms are present.


Culture with Gram stain: Of the lesion to identify the causative organism.

Complete blood count: May show an elevated white blood cell count with systemic infections.

Differential Diagnosis


Wounds: Especially those of the puncture or penetrating type, may lead to infections with less common, more difficult bacteria, (e.g., Tetanus welchi, P. aeruginosa, etc.) which require specialized antibiotic treatment or tetanus innoculation.


Fungal kerions: Can mimic boils, abscesses, furuncles, or carbuncles and may even be colonized with double infection. Usually less inflammation with lesions solely due to fungal organisms, but only culturing will differentiate. Most common on scalp.

Folliculitis (Fungus and chemical): Including steroids, (e.g., cortisones, androgens). Differentiated by resistance to treatment, potassium hydroxide (KOH) preparations, Gram stains, and/or cultures of intrafollicular matter.

Pityrosporum orbiculare: Most common fungal/yeast pathogen. Occasional P. aeruginosa seen with a history of frequent whirlpool or hot tub use.

Herpes virus: In crusted ulcer stage can look like impetigo, but recurrent history, location, and prodrome are different.

Tularemia: is a gram-negative bacillus disease from Francisella tularensis causing ecthyma like ulcers. Usually seen on the arms and hands of rabbit handlers. May occur anywhere on the body if due to tick borne disease.

Ulcers: Few, just at site of skin entry. Respond to streptomycin or gentamycin.

Metabolic: Not applicable.


Some basal, squamous cell cancer, and metastatic lesions to the skin: May appear as furuncles, carbuncles, abscesses, or ulcerations. Their chronic non tender sterile nature differentiates.

Vascular: Not applicable.

Congenital: Not applicable.

Acquired: Not applicable.


Boils and Abscesses: Uncomplicated with no cellulitis: Usually heal after sterile incision and drainage accomplished with sterile #11 blade and local anesthetic or Frigiderm topical freeze anesthesia. If ripe pustular point is present, no anesthesia may be required. Hot compresses may be applied 15 to 30 minutes 2 to 3 times daily until the lesion dries out. This is performed if there is no drainage and the lesion is healed closed. If large, (greater than 2 cm) a gauze or rubber drain may facilitate healing. Remove after 3 to 5 days. If complicated by number of lesions or gangrene, or serious host immunodeficiency or cellulitis systemic disease signs, then systemic antibiotics may be needed after Gram stain and culture.

Antibiotic therapy consists of: Dicloxacillin 250 mg four times a day for adults, or erythromycin 250 to 500 four times a day for 10 days (Adults, under 60 lbs. 125 mg four times a day), or azithromycin 250 mg 2 capsules together day one then one daily for 4 days, or ceclor 500 mg twice a day. Clindamycin in recommended doses is an alternative in penicillin or cephalosporin allergic patients.

Furuncles and carbuncles: For a small number of lesions, moist heat and/or incision and drainage usually is curative. If the lesions are widespread or there is significant surrounding inflammation cellulitis, use systemic antibiotics as listed above for abscesses.

Folliculitis: Tetracycline 250 mg one four times a day or two twice a day up to 6 weeks and longer. Erythromycin 250 mg four times a day or two twice a day up to 6 weeks and longer. Avoid hot tubs if suspected as a cause, stop oil contact and chronic friction (e.g., tight clothes).Other antistaphylococus antibiotics may be used.

Impetigo: If there are less than 3 lesions, small, treat with topical mupirocin, bacitracin, or other topical antibiotic preparations.

Dicloxacillin 250 mg four times a day best for thick or thin crusting or bullous lesions caused by Staphylococcus and/or Streptococcus.

Erythromycin 250 to 500 mg four times a day for first line therapy or in those who are penicillin-allergic.Clindamycin 150 mg four times a day or a cepholosporin (e.g., Cefalexin 250 mg four times a day) may be used as an alternative. All antibiotics are given for 7 to 14 days.

Ecthyma: Dicloxacillin, erythromycin, clindamycin, or cephalosporin as dosed for impetigo above.

Erysipelas and cellulitis: Penicillin V 250 to 500 mg four times a day 10 days or Bicillin CR 2 ml intramuscularly for adult or erythromycin 250 to 500 mg four times a day for 10 days or clindamycin 150 mg four times a day for 10 days or a first generation cephalosporin equivalent to cephalexin 250 to 500 mg four times a day for 10 days.

Obstetrical Considerations

Sulfonamides, erythromycin, and ciprofloxacin should be used with caution. Tetracycline is contraindicated.

More Skin Disorders
   Langerhans Cell Histiocytosis
   Leg Ulcers
   Lentigo Maligna
   Leukemia Cutis
   Livedo Reticularis
   Localized Infection
   Lupus Erythematosus
   Lyme Borreliosis
   Lymphogranuloma Venereum
   Lymphomatoid Papulosis
   Malignant Melanoma of the Mucosa
   Mammary Paget's Disease
   Mastocytosis Syndromes
   Merkel Cell Carcinoma
   Metastatic Cancer to the Skin
   Molluscum Contagiosum
   Mycobacterium Fortuitum Complex Infection
   Mycobacterium Marinum Infection
   Mycobacterium Ulcerans Infection
   Necrobiosis Lipoidica
   Neisseria Gonorrhoeae Infections
   Nodular Melanoma
   Nodular Vasculitis
   Nongenital Herpes Simplex Virus Infection
   North American Blastomycosis
   Oral Hairy Leukoplakia
   Oropharyngeal Candidiasis
   Other Viral Infections
   Papulosquamous Conditions
   Pediculosis Capitis
   Pediculosis Pubis
   Photoallergic Drug Induced Photosensitivity
   Phototoxic Drug Induced Photosensitivity
   Pitted Keratolysis
   Pityriasis Versicolor
   Polyarteritis Nodosa
   Polymorphous Light Eruption
   Porphyria Cutanea Tarda
   Port-Wine Stain
   Premalignant and Malignant Skin Tumors
   Pressure Ulcers
   Pruritic Urticarial Papules
   Pseudoxanthoma Elasticum
   Pyogenic Granuloma
   Radiation Dermatitis
   Raynaud's Disease
   Reiter's Syndrome
   Rocky Mountain Spotted Fevers
   X-Linked Hyper-IgM Syndrome
   Xeroderma Pigmentosum
   Yellow Fever
   Yellow Nail Syndrome
   Zinc Deficiency

Skin Disorders || Contact Us || Tweet

Copyright © All Rights Reserved.

Disclaimer - The data contained in the Web pages is provided for the purpose of educational purposes and information only. It is not intended nor implied to be a substitute for professional medical advice and shall not create a physician - patient relationship. We are not responsible for any consequence resulted from using this information. Please always consult your physician for medical advices and treatment.