Bacteral nfectons

mpetgo caused by Staphylococcus aureus may be severe wth large bullous lesons assocated wth strans producng exfolatve toxns A/B. Erythrasma (Corynebacterum) may be persstent and recurrent n the flexural areas and often mstaken for a superfcal fungal nfecton.

Bartonella henselae and B. quntana nfectons can cause bacllary angomatoss (BA) n ADS patents, who present wth multple small haemangoma-lke papules on the skn and mucous membranes. Skn lesons develop slowly over several weeks (Fgure 15.7), and vsceral organs may also be affected - most commonly the lver. The dfferental dagnoss usually ncludes Kapos’s sarcoma. Blood cultures are usually dagnostc but the laboratory must be alerted to the possblty of Bartonella as blood cultures must be ncubated for 3 weeks under specfc condtons. Skn bopsy for hstology s usually dagnostc. Bartonella are hghly senstve to macrolde antbotcs whch are bacterostatc and therefore an ant-angogenc effect through down-regulaton of endothelal cells has been postulated as the mechansm of acton n BA. The treatment of choce s erythromycn 500 mg qds for up to 12 weeks. Azthromycn 500 mg on the frst day and then 250 mg daly for 5 days s also hghly effectve.

Fgure 15.8 Secondary syphls.

Syphls

Approxmately 12 mllon new cases of syphls nfecton are reported each year accordng to the WHO, wth a notable resurgence n many parts of the world where the ncdence was prevously low. Between 20 and 70% of patents n the USA and Europe are co-nfected wth HV and syphls smultaneously. Syphls s caused by the spral bacterum (sprochaete) Treponema palldum. Syphls s the great mmcker of other dseases and n the context of HV nfecton presentatons may be atypcal.

Classcally a panless gental ulcer develops 3-4 weeks after transmsson va sexual ntercourse. Secondary syphls presents wth a rash, fever, arthralga and lymphadenopathy 4-8 weeks after the ntal nfecton. The rash s usually asymptomatc and characterstcally affects the trunk, palms and soles. Early lesons are usually annular erythematous macules that fade to a greysh-brown (Fgure 15.8). Serologcal testng for syphls should be performed to confrm the dagnoss. Prmary/secondary syphls should be treated wth a sngle dose of ntramuscular benzathne penclln 2.4 megaunts, or ntramuscular procane penclln 600 000 unts daly for 10 days. Latent syphls requres prolonged treatment.

Fgure 15.9 HSV (mmune reconsttuton nflammatory syndrome, RS).

Mycobactera may produce wdespread cutaneous and systemc lesons. Varetes of mycobactera that do not normally nfect the skn may cause persstent necrotc papules or ulcers.

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