DefinitionErysipelas is a superficial bacterialskin infection that is characteristicallyextends into cutaneous lymphatics .It was referred to as : Saint Anthonys Fire (= ergotism orerysipelas or Herpes zoster )
Pathophysiology •Bacterial inoculation into an area of skin traumais the initial event in developing erysipelas.
Pathophysiology The source of the bacteria in facial erysipelas is often the hosts naso- pharynx, and a history of recent streptococcal pharyngitis has been reported in up to one third of cases.
PathophysiologyLymphoscintigraphy in patientswith a first-time episode oflower extremity erysipelas hasdocumented lymphaticimpairment in both affectedand non affected legs.
Causative organism* Streptococci are the primarycause of erysipelas.* Most facial infections areattributed to group Astreptococci,*lower extremity infectionsbeing caused by non–group Astreptococci.
causes•Streptococcal toxins are thought tocontribute to the brisk inflammationthat is pathognomonic of this infection.*No clear proof has emerged that otherbacteria cause typical erysipelas,although they clearly coexist withstreptococci at sites of inoculation.
causesRecently, atypical forms reported to becaused by : * Streptococcus pneumoniae, *Klebsiella pneumoniae, * Haemophilus influenzae, *Yersinia enterocolitica, *Moraxella species,they should be considered in cases refractoryto standard antibiotic therapy.
RaceErysipelas infections affect persons of allraces. Sex•Erysipelas is common in females.• at an earlier age it is more in males ( moreactivities).• However predisposing factors, rather thangender, account for any male/femaledifferences in incidence.
Age All age groups are susiptable.The peak incidence at 60-80 yearsold, especially in patients := At high-risk .= immuno-compromised .= those with lymphatic drainageproblems (eg, after mastectomy, pelvicsurgery, bypass grafting).
Erythema Annulare Centrifugum* Eruptions occur at anyage. * begins as small raisedpink-red spot that slowlyenlarges and forms a ringshape while the centralarea flattens and clears.There may be an innerrim of scale.
Erythema Annulare CentrifugumLesions most oftenappear on thethighs, legs, face, trunkand arms.linked to underlyingdiseases , viral, bacterial or eventumor.
Erysipeloid * acute bacterial infection of traumatized skin. * caused by Erysipelothrix rhusiopathiae(gram positive rod-shaped bacterium), whichcause animal and human infections. * Direct contact between infected meat andtraumatized human skin results in Erysipeloid.•more common amongfarmers, butchers, cooks, homemakers. * Lesions most commonly affect the hands.
Erysipeloid * Lesions consist of well- demarcated, brightred-to-purple plaques with a smooth, shiny surface. •Lesions are warm and tender.
Laboratory Studies* In classic erysipelas, nolaboratory workup is requiredfor diagnosis or treatment.* Cultures are best reserved forimmunocopromized patient inwhom an atypical etiologic agentis suspected.
Imaging StudiesImaging studies are not usuallyindicated and are of low yield.MRI and bone scintigraphy arehelpful when early osteoarticularinvolvement is suspected. In this setting, standardradiographic findings typically arenormal.
Histological FindingsThe histological hallmarks of erysipelas are*marked dermal edema,*vascular dilatation,*streptococcal invasion of lymphatics & tissues.This bacterial invasion results in a dermalinflammatory infiltrate consisting ofneutrophils and mononuclear cells. The epidermis is often secondarily involved.Rarely, bacterial invasion of local blood vesselsmay be seen.
Hospitalization for close monitoringand IV. antibiotics is recommendedfor :1) severe cases.2) infants.3) elderly patients.4) patients who are immune- compromised.
Medical Care* Elevation and rest of the affectedlimb are recommended to reducelocal swelling, inflammation, and pain.* Saline wet dressings should beapplied to ulcerated and necroticlesions and changed every 2-12 hours,depending on the severity of theinfection.
Medical Care* penicillin has remained first-line therapy. administered orally or IM. for 10-20 days.Dosing : AdultPenicillin G procaine: 0.6-1.2 million U IM bid for 10 dPenicillin VK: 250-500 mg PO qid for 10-14 dPediatric : Penicillin G procaine: <30 kg: 300,000 U/d >30 kg: Administer as in adults Penicillin VK:<12 years: 25-50 mg/kg/d PO divided tid/qid; not to exceed 3 g/d>12 years: Administer as in adults
Medical Care*A first-generation cephalosporin ormacrolide, such as erythromycin orazithromycin, may be used if the patient hasan allergy to penicillin.DosingAdult250-500 mg PO qid for 10 dPediatric30-50 mg/kg/d (15-25 mg/lb/d) PO dividedq6-8h; double dose for severe infection.
•Two new drugs:• roxithromycin & pristinamycin, have been reported to be extremelyeffective in the treatment of erysipelas.* Several studies have demonstrated greaterefficacy and fewer adverse effects withthese drugs compared with penicillin.*Currently, FDA has not approved thesedrugs in the United States, but they are inuse in Europe.
Recurrent erysipelas•Long-term prophylactic antibiotic therapygenerally is accepted, but no true guidelines areavailable.•Treatment regimens should be tailored to thepatient.•One reported regimen is benzathinepenicillin G at 2.4 MU IM. every 3 weeksfor up to 2 years . Two-week intervalshave also been used.
Surgical CareDebridement is necessaryonly in severe infectionswith necrosis or gangrene.