No abstract

In our region, P. acnes is highly resistant to azithromycin, SXT, erythromycin and clindamycin; and being very susceptible to minocycline, levofloxacin and tetracycline, in vitro in both groups: with and without the previous antibiotic use. To our knowledge, high resistance prevalence to azithromycin and SXT has never been reported.

A 40-year-old homosexual HIV-positive patient, who was under highly active antiretroviral therapy (HAART), presented with an ulcerative lesion in the left supraclavicular region. A biopsy from it revealed a granulomatous tissue reaction where the acid-fast bacilli stains and culture for mycobacteria were negative, and both the coccidiodin and tuberculin skin tests were also negative. Polymerase chain reaction (PCR) was performed and was positive for Mycobacterium tuberculosis (MT). Identification was carried out using a fresh tissue sample with an "in-house" system using three sets of primers, including INS1-INS2, TB1-TB2, TB11-TB12, which amplify a fragment of the right-arm of the insertion element IS6110, a specific MT sensu stricto gene fragment (mtp40), and a fragment of hsp65 gene, respectively. 1,2 The latter test allowed (after digesting the amplicons with the appropriated restriction enzymes) the recognition of mycobacterium other than tuberculosis (MOTT) such as M. marinum, M. avium, M. chelonae, or M. abscessus. After PCR was completed, 20 µL was applied to a 1.5% agarose gel to determine the positivity of each sample. Therapy was started with isoniazid, rifampin, ethambutol and pyrazinamide and after a year of treatment the lesion had completely disappeared, and the patient remained asymptomatic at the time of writing. Case 2A 34-year-old male presented with a verrucous plaque in the left inguinal region with an ulcer in the center and associated adenomegaly of 25 years' maturity ( Fig. 1). The tuberculin and coccidioidin skin tests were positive with an induration greater than 10 mm. The histopathologic study revealed granulomatous tissue, and no micro-organisms were demonstrated with either PAS or Ziehl-Neelsen stains. The PCR was performed, as described previously, and a positive result for MT was obtained. After 2 months of antituberculous therapy (same scheme as in Case 1) an important improvement of the lesions was observed and after 7 months of treatment the patient was asymptomatic. Figure 1 Inguinal ulcer and associated adenomegaly of 25 years' maturity

Two patients, one man aged 65 and one woman aged 48, presenting generalized lichen nitidus are reported. The clinical and histopathologic features of this uncommon presentation of lichen nitidus are illustrated as well as the excellent clinical response to the treatment with an H1-blocking antihistaminic (astemizol).