The value of axillary skin electron microscopic analysis in the diagnosis of lysosomal storage disorders

Both lysosomal storage diseases and mitochondrial diseases are a group of genetic-inherited metabolic disorders. In an era, where "old fashioned methods" are apparently being replaced by evolving molecular techniques (i.e. exome and whole genome sequencing), the "old fashioned methods" might help to characterise and thus narrow down the potential differential diagnosis. Therefore, we retrospectively evaluated the relevance of electron microscopy of axillary skin for the diagnosis of lysosomal storage or mitochondrial diseases (=inherited metabolic disorders of energy metabolism). Methods and patients: We included 74 patients with developmental delay with regression or neurodegeneration who underwent an axillary skin biopsy for both fibroblast culture and electron microscopy. Because of insufficient skin biopsy quality, for 8 patients no electron microscopy result was obtained. The electron microscopy biopsies revealed abnormalities in 37/66 (56.1%) patients. 29/66 electron microscopy biopsies showed normal results. A definite diagnosis was established in 21/66 (31.8%) patients with a pathological results of axillary skin electron microscopy analysis. In total, in 25/66 (37.8%) of the patients who underwent an axillary skin electron microscopy analysis, a definite diagnosis was finally established. Taking an axillary skin biopsy during anaesthesia or with use of local intradermal lidocaine application is an inexpensive alternative and useful to establish a diagnosis in patients suspected to have a lysosomal storage disease (or inherited metabolic disorder of energy metabolism).

Cyclospora cayetanensis: first imported infections in Germany

Over the last decade increasing numbers of enteritis cases have been attributed to infection with a new coccidian species that was named Cyclospora cayetanensis in 1993. Diarrhea caused by this agent is clinically indistinguishable from cryptosporidiosis, isosporiasis and microsporidiosis, but Cyclospora infections are often very prolonged (up to 15 weeks) and may cause severe weight loss. Diagnosis of infection is important because, in contrast to diarrhea caused by Cryptosporidium and microsporidia, treatment with co-trimoxazole is effective. Here we report the cases of two female patients, aged 70 and 58 years old, respectively, who suffered from severe, prolonged diarrhea after a vacation in Singapore, Java and Bali. Routine microbiological laboratory diagnostics were unable to demonstrate the presence of known enteropathogenic bacteria. Modified Ziehl-Neelsen staining of fecal smears revealed oocysts of Cyclospora cayetanensis, and treatment of the patients with co-trimoxazole was promptly effective. We would like to increase awareness of the possibility of Cyclospora infections in patients with prolonged diarrhea who have travelled to endemic areas.