Neurorétinite unilatérale révélant une maladie des griffes du chat

Seek and Find! PCR analyses of skin infections in West-European travelers returning from abroad with an eschar

BACKGROUND

Skin infections are among the leading causes of diseases in travelers. Diagnosing pathogens could be difficult.

METHOD

We applied molecular assays for the diagnostic of a large collection of skin biopsies and swabs from travelers with suspected skin infections. All samples were tested by qPCR for Coxiella burnetti, Bartonella sp., Rickettsia sp., Borrelia sp., Ehrlichia sp., Tropheryma whipplei, Francisella tularensis, Mycobacteria sp., Staphylococcus aureus, Streptococcus pyogenes, Leishmania spp., Ortho poxvirus and Para poxvirus and then screened for the presence of bacteria by PCR amplification and sequencing, targeting the 16S rRNA gene.

RESULTS

From January 2009 to January 2017, 100 international travelers presenting with a suspected skin infection were enrolled. We detected 51 patients with an identified pathogen on skin samples. Travelers presenting with eschars were more likely to have a positive PCR sample (n = 44/76, 57.9%) compared to other patients (n = 7/24, 29.2%). Spotted fever group Rickettsia (n = 28) was the most frequently detected pathogens (19 R. africae, 6 R. conorii, 3 R. mongolitimonae); S. aureus were detected in 11 patients; S. pyogenes in 3; Leishmania sp.; M. leprae and B. henselae in 1 patient, respectively.

CONCLUSION

By targeting the most commonly encountered causative agents of travel-related skin infections, our strategy provides a sensitive and rapid diagnostic method.

[Preauricular lymphadenopathy related to Bartonella henselae]

INTRODUCTION

Cat scratch disease is characterized by adenitis with usually positive outcome. We reported two cases of cat scratch disease with preauricular involvement occurring in immunocompetent patients.

OBSERVATIONS

Observation 1: a 28-year-old man had a recent onset of left cervical swelling, with a peripheral facial paralysis and liver cytolysis. Serologies for EBV, viral hepatitis, CMV, HIV and toxoplasma were negative. Node excision biopsy suggested granulomatous lymphadenitis and Bartonella henselae PCR on lymph node was positive. With doxycyclin for 3 months, associated with rifampicin for 15 days, abnormal liver function disappeared and facial paralysis improved. Observation 2: a 17-year-old man had parotid swelling associated with right posterior cervical lymphadenopathies associated with fever and profuse sweating. A large right preauricular lymphadenopathy with necrotic remodeling was visible on the CT-scan. Lymph fluid B. henselae PCR was positive. Positive outcome occurs after surgical drainage and short azithromycin treatment.

CONCLUSION

Physicians should be aware of the rare preauricular localization of cat scratch disease and ask for contact with a cat. Parotid tumor localization, lymphoma or tuberculosis should be ruled out. Diagnosis is based on the B. henselae PCR. Outcome is often spontaneously positive but surgical treatment may be required.

[Bilateral stellate neuroretinitis as presenting sign of pheochromocytoma]

We report the case of a 21-year-old male patient admitted emergently with progressive bilateral severe visual loss for 1 month. Posterior segment examination revealed bilateral stellate neuroretinitis. Infectious serologies were negative, and brain CT was normal. Physical examination was remarkable for malignant hypertension of 220/150 mmHg. Diagnostic work-up revealed a pheochromocytoma documented by histopathological exam upon adrenalectomy. The disc edema and macular exudates resolved once the hypertension was controlled.