Human dirofiliariasis in Croatia.

Dear Editor, I read with great interest the article "Subcutaneous dirofilariasis caused by Dirofilaria repens diagnosed by histopathologic and polymerase chain reaction analysis", published in the last issue of Acta Dermatovenerologica Croatica. The authors of the article describe a case of human dirofilariasis with typical subcutaneous presentation of the parasite. They cite this case as the fourth reported case of the disease in Croatia (1). However, dirofilariasis in Croatia has been reported more frequently than it looks at the first glance. The main reason for this discrepancy is that some cases have been reported in journals and other publications with poor or no visibility. The first case reported was the case of conjunctival dirofilariasis described by Bujger et al. in 1996, published in Ophthalmologia Croatica. Unaware of this case, due to its invisibility in the main journal databases, in 2003 Puizina-Ivić et al. reported two cases of the disease as the first cases of human dirofilariasis in Croatia. Actually, these were the first reported cases of the subcutaneous form of the disease in our country, followed by the case presented as subcutaneous mammary nodule (3,4). All of these subcutaneous cases were from the southern part of Croatia, where additional cases were frequently encountered and reported (5,6). In 2007, another case of ocular dirofilariasis was reported, followed by two reported cases of the subcutaneous form of the disease, all from the inland part of Croatia (7,8). In all of the reported cases, Dirofilaria repens was identified as the causative agent. Altogether, including the case reported in your journal, at least 10 human cases of this emerging zoonosis have been reported in Croatia so far, confirming the conclusion by Marusić et al. that Croatia represents an endemic area, like other countries in the Mediterranean basin (1). As the majority of cases presented as subcutaneous nodules, dermatologists and dermatopathologists should familiarize themselves with the clinical and histologic aspects of the disease, considering it in the differential diagnosis of solitary nodules in subcutaneous tissue.