AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

INTRODUCTION

Section 2 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

Background

Ecthyma is an ulcerative pyoderma of the skin caused by group A beta-hemolytic streptococci. Because ecthyma extends into the dermis, it is often referred to as a deeper form of impetigo. See Impetigo for more information.

Pathophysiology

Ecthyma begins similarly to superficial impetigo. Group A beta-hemolytic streptococci may initiate the lesion or may secondarily infect preexisting wounds. Preexisting tissue damage (eg, excoriations, insect bites, dermatitis) and immunocompromised states (eg, diabetes, neutropenia) predispose patients to the development of ecthyma. Spread of skin streptococci is augmented by crowding and poor hygiene.

Frequency

International

The exact incidence worldwide remains unknown.

Mortality/Morbidity

Ecthyma rarely leads to systemic symptoms or bacteremia. Lesions are painful and can have associated lymphadenopathy. Secondary lymphangitis and cellulitis can occur. Ecthyma does heal with scarring. The rate of poststreptococcal glomerulonephritis is approximately 1%.

Race

No racial predisposition is recognized.

Sex

No sexual predisposition is recognized.

Age

Ecthyma has a predilection for children and elderly individuals.

CLINICAL

Section 3 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

History

• Ecthyma usually arises on the lower extremities of children, persons with diabetes, and neglected elderly patients.
• During wartime in tropical climates, ecthymatous ulcers are commonly found on the ankles and dorsi of the feet.

Physical

• Ecthyma begins as a vesicle or pustule overlying an inflamed area of skin that deepens into a dermal ulceration with overlying crust.
• • The crust is gray-yellow and is thicker and harder than the crust of impetigo.
  • A shallow, punched-out ulceration is apparent when adherent crust is removed.
  • The deep dermal ulcer has a raised and indurated surrounding margin.
• Ecthyma lesions can remain fixed in size (sometimes resolving without treatment) or can progressively enlarge to 0.5-3 cm in diameter.
• Ecthyma heals slowly and commonly produces a scar.
• Regional lymphadenopathy is common, even with solitary lesions.

Causes

• Ecthyma can be seen in areas of previously sustained tissue injury (eg, excoriations, insect bites, dermatitis).
• Ecthyma can be seen in patients who are immunocompromised (eg, diabetes, neutropenia).
• Important factors contribute to the development of streptococcal pyodermas or ecthyma.
• • High temperature and humidity¹
  • Crowded living conditions
  • Poor hygiene
• Untreated impetigo that progresses to ecthyma most frequently occurs in patients with poor hygiene.

DIFFERENTIALS

Section 4 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

Other Problems to be Considered

Cutaneous diphtheria
Other bacterial, viral, and deep fungal infections of the skin
Excoriated insect bites
Ulcers of venous and arterial insufficiency

WORKUP

Section 5 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

Lab Studies

Gram stain and culture of ecthyma lesions reveal gram-positive cocci that represent group A streptococci, with or without Staphylococcus aureus. Prior group A streptococci infection can be detected by anti-DNase beta testing.

Histologic Findings

Ecthyma lesions show dermal necrosis and inflammation. A deep and superficial granulomatous perivascular infiltrate occurs along with endothelial edema. A heavy crust covers the surface of the ecthyma ulcer.

TREATMENT

Section 6 of 10  

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• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

Medical Care

Medical treatment depends on the progression of the lesions. Hygiene is important. Maintain cleanliness by using bactericidal soap and frequently changing bed linens, towels, and clothing. Remove crusts by soaking or using wet compresses and apply an antibiotic ointment daily.

• Consider topical therapy with mupirocin ointment for localized ecthyma.²
• More extensive lesions require oral antibiotics; the duration of treatment varies because ecthyma may require several weeks of therapy to completely resolve.
• Penicillin should be adequate to treat ecthyma.
• Oral antistaphylococcal agents (eg, dicloxacillin, cephalexin, erythromycin, clindamycin) have been used to cover possible secondary S aureus infections. A study by Kelly et al³ has demonstrated that benzathine penicillin G eradicates streptococci; lesions heal clinically despite the concomitant presence of staphylococci.
• Consider parenteral antibiotics for widespread involvement.

Surgical Care

Gently debride crusts.

MEDICATION

Section 7 of 10  

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• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

The goals of pharmacotherapy are to reduce morbidity and to prevent complications.

Drug Category: Antibiotics

Topical antibiotics should be considered adjunctive therapy in addition to systemic antibiotics for the treatment of ecthyma.

Drug Name	Penicillin VK (Veetids, Beepen-VK)
Description	Inhibits biosynthesis of cell wall mucopeptide and is effective during stage of active multiplication. Inadequate concentrations may produce only bacteriostatic effects.
Adult Dose	0.25-0.5 g PO qid
Pediatric Dose	25-50 mg/kg/d divided q6-8h
Contraindications	Documented hypersensitivity
Interactions	Probenecid can increase effects by decreasing clearance; coadministration of tetracyclines can decrease effects
Pregnancy	B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions	Caution in impaired renal function

Drug Name	Erythromycin (E.E.S., E-Mycin, Ery-Tab)
Description	Suitable alternative for patients who are allergic to penicillin. Inhibits bacterial growth, possibly by blocking dissociation of peptidyl t-RNA from ribosomes, causing RNA-dependent protein synthesis to arrest. For treatment of staphylococcal and streptococcal infections. In children, age, weight, and severity of infection determine proper dosage. When bid dosing is desired, half-total daily dose may be taken q12h. For more severe infections, double the dose.
Adult Dose	250-500 mg PO qid
Pediatric Dose	30-50 mg/kg/d PO divided q8-12h
Contraindications	Documented hypersensitivity; hepatic impairment
Interactions	Coadministration may increase toxicity of theophylline, digoxin, carbamazepine, and cyclosporine; may potentiate anticoagulant effects of warfarin; coadministration with lovastatin and simvastatin increases risk of rhabdomyolysis; coadministration of strong CYP3A inhibitors (eg, diltiazem, verapamil, nitroimidazole antifungal agents) increases risk of sudden death from ventricular arrhythmias
Pregnancy	B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions	Caution in liver disease; estolate formulation may cause cholestatic jaundice; adverse GI effects are common (give doses pc); discontinue use if nausea, vomiting, malaise, abdominal colic, or fever occur

Drug Name	Cephalexin (Keflex, Biocef)
Description	First-generation cephalosporin arrests bacterial growth by inhibiting bacterial cell wall synthesis. Bactericidal activity against rapidly growing organisms. Primary activity against skin flora; used for skin infections or prophylaxis in minor procedures. Active against Streptococcus pyogenes and S aureus.
Adult Dose	250-500 mg PO qid
Pediatric Dose	25-50 mg/kg/d PO divided qid
Contraindications	Documented hypersensitivity
Interactions	Coadministration with aminoglycosides increases nephrotoxic potential
Pregnancy	B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions	Patients with a history of IgE-mediated allergic reactions to penicillin may have similar reactions to cephalosporins; adjust dose in renal impairment

Drug Name	Clindamycin (Cleocin)
Description	Lincosamide for treatment of serious skin and soft tissue staphylococcal infections. Also effective against aerobic and anaerobic streptococci (except enterococci). Inhibits bacterial growth, possibly by blocking dissociation of peptidyl t-RNA from ribosomes, causing RNA-dependent protein synthesis to arrest.
Adult Dose	150-300 mg PO qid
Pediatric Dose	10-20 mg/kg/d PO divided tid/qid
Contraindications	Documented hypersensitivity; regional enteritis, ulcerative colitis, hepatic impairment, antibiotic-associated colitis
Interactions	Increases duration of neuromuscular blockade induced by tubocurarine and pancuronium; erythromycin may antagonize effects; antidiarrheals may delay absorption
Pregnancy	B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions	Adjust dose in severe hepatic dysfunction; no adjustment necessary in renal insufficiency; associated with severe and possibly fatal colitis

Drug Name	Dicloxacillin (Dycill, Dynapen)
Description	Treatment of infections caused by penicillinase-producing staphylococci. May use to initiate therapy when staphylococcal infection is suggested.
Adult Dose	125-500 mg PO qid
Pediatric Dose	12.5-50 mg/kg/d PO divided into 4-6 doses
Contraindications	Documented hypersensitivity
Interactions	Probenecid may increase effect of penicillins; tetracyclines may decrease effect of penicillins with concurrent use
Pregnancy	B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions	Caution in impaired renal function

Drug Name	Mupirocin (Bactroban)
Description	Selectively binds to bacterial isoleucyl transfer-RNA synthetase, inhibiting protein synthesis.
Adult Dose	Apply thin film to affected area bid
Pediatric Dose	Administer as in adults
Contraindications	Documented hypersensitivity
Interactions	None reported
Pregnancy	B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions	Prolonged use may result in growth of nonsusceptible organisms; local reactions have been reported (ie, burning, pain, pruritus, erythema, dry skin, tenderness, cellulitis)

FOLLOW-UP

Section 8 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

Deterrence/Prevention

• Maintaining cleanliness is critical for preventing ecthyma.
• Using insect repellants to prevent bites also may decrease the prevalence of this infection.

Complications

• Ecthyma rarely produces systemic symptoms.
• Invasive complications of streptococcal skin infections include cellulitis, erysipelas, gangrene, lymphangitis, suppurative lymphadenitis,⁴ and bacteremia.
• Nonsuppurative complications of streptococcal skin infections include scarlet fever and acute glomerulonephritis. Prompt antibiotic therapy does not appear to reduce the rate of poststreptococcal glomerulonephritis.
• Possible sequelae of secondary untreated S aureus pyodermas include cellulitis, lymphangitis, bacteremia, osteomyelitis, and acute infective endocarditis. Some S aureus strains produce exotoxins that can lead to staphylococcal scalded skin syndrome and toxic shock syndrome.

Prognosis

• Ecthyma lesions are slow to heal but do respond to appropriate antibiotics over several weeks; prognosis is favorable.

Patient Education

• For excellent patient education resources, see eMedicine's Skin, Hair, and Nails Center. Also, see eMedicine's patient education article Impetigo.

MULTIMEDIA

Section 9 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

Media file 1:  Typical ecthyma lesions of the lower extremities.
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Media type:  Photo

Media file 2:  The stages of ecthyma. The lesion begins as a pustule that later erodes and ultimately forms an ulcer.
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Media type:  Photo

REFERENCES

Section 10 of 10

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
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• Follow-up
• Multimedia
• References

1. Singh G. Heat, humidity and pyodermas. Dermatologica. 1973;147(5):342-7. [Medline].
2. Dagan R, Bar-David Y. Double-blind study comparing erythromycin and mupirocin for treatment of impetigo in children: implications of a high prevalence of erythromycin-resistant Staphylococcus aureus strains. Antimicrob Agents Chemother. Feb 1992;36(2):287-90. [Medline].
3. Kelly C, Taplin D, Allen AM. Streptococcal ecthyma. Treatment with benzathine pencillin G. Arch Dermatol. Mar 1971;103(3):306-10. [Medline].
4. Duve S, Voack C, Rakoski J, Hoffmann H. Extensive inguinal lymphadenitis. Ecthyma with inguinal lymphadenitis. Arch Dermatol. Jul 1996;132(7):823, 826. [Medline].
5. Allen AM, Taplin D, Twigg L. Cutaneous streptococcal infections in Vietnam. Arch Dermatol. Sep 1971;104(3):271-80. [Medline].
6. Dagan R. Impetigo in childhood: changing epidemiology and new treatments. Pediatr Ann. Apr 1993;22(4):235-40. [Medline].
7. Epstein ME, Amodio-Groton M, Sadick NS. Antimicrobial agents for the dermatologist. I. Beta-lactam antibiotics and related compounds. J Am Acad Dermatol. Aug 1997;37(2 Pt 1):149-65; quiz 166-8. [Medline].
8. Hewitt WD, Farrar WE. Bacteremia and ecthyma caused by Streptococcus pyogenes in a patient with acquired immunodeficiency syndrome. Am J Med Sci. Jan 1988;295(1):52-4. [Medline].
9. Jain A, Daum RS. Staphylococcal infections in children: Part 1. Pediatr Rev. Jun 1999;20(6):183-91. [Medline].
10. Ko WT, Adal KA, Tomecki KJ. Infectious diseases. Med Clin North Am. Sep 1998;82(5):1001-31, v. [Medline].
11. Leyden JJ, Kligman AM. Rationale for topical antibiotics. Cutis. Oct 1978;22(4):515-20, 522-8. [Medline].
12. Peter G, Smith AL. Group A streptococcal infections of the skin and pharynx (first of two parts). N Engl J Med. Aug 11 1977;297(6):311-7. [Medline].
13. Pichichero ME. Group A beta-hemolytic streptococcal infections. Pediatr Rev. Sep 1998;19(9):291-302. [Medline].
14. Ray WA, Murray KT, Meredith S, Narasimhulu SS, Hall K, Stein CM. Oral erythromycin and the risk of sudden death from cardiac causes. N Engl J Med. Sep 9 2004;351(11):1089-96. [Medline].
15. Sadick NS. Current aspects of bacterial infections of the skin. Dermatol Clin. Apr 1997;15(2):341-9. [Medline].
16. Witkowski JA, Parish LC. Bacterial skin infections: management of common streptococcal and stapylococcal lesions. Postgrad Med. Oct 1982;72(4):166-8, 171-3, 176-8 passim. [Medline].

Article Last Updated: Feb 28, 2007