Notalgia paresthetica: The histopathological findings of 17 cases

Abstract

Introduction: Notalgia paresthetica (NP) is a chronic disease characterized by sensory neuropathy which holds the skin, characterized by pruritus in which pain, paresthesia and/or hypersthesia were concomitant, and accompanied by remission and aggravation. Although NP is a common condition, it is rarely diagnosed by clinicians. For this reason, there are not too many series with many cases in the literature investigating this entity. In this study, we tried to reveal the histopathological findings of NP in the series with the highest number of cases in the literature and contribute to the clarification of the pathogenesis of the disease. Materials and methods: Punch biopsy materials of 17 patients diagnosed with notalgia parestetica in Corum Erol Olcok Education and Research Hospital were included in the study. 4 mm diameter punch biopsy material was obtained from each patient. Tissues were embedded in paraffin blocks and after fixation, 5 pieces of sections with 4 micron thickness were obtained from each tissue with a microtome device. Three of the sections were stained with Hematoxylin Eosin, 1 of them were stained with Crystal violet for amyloid determination and 1 of them were stained with Perioidic Acid Schiff (PAS) for the detection of fungi and vasculitis. The satined slights were examined in light microscope (Nikon Ci). Each slights were evaluated by a single pathologist in detail in terms of epidermal changes and dermal changes. Results: Of the 17 patients included in the study, 13 (76.5%) were female and 4 (23.5%) were male. The age of the patients ranged from 19 to 63 years, with an average of 44.2 years. Epidermal changes were detected in 8 (47%) cases. The average age of the patients with epidermal changes was 31.6 years and the average age of the patients without epidermal changes was 48.7 (p < 0.001) Hyperpigmentation in the basal of the epidermis was seen in 3 (17.6%) cases. The two most common findings in dermis were perivascular lymphocytes and melanophages. Perivascular lymphocyte infiltration was observed in 15 (88.2%) cases while melanophages were observed in 13 (76.4%) cases. Amyloid accumulation was not detected in any of the 17 cases with crystal violet. In 2 cases lymphocytic vasculitis was observed in the dermis. Conclusion: NP is a chronic disease accompanied by epidermal and dermal changes. The most common epidermal change is single cell necrosis and dermal change is perivascular lymphocyte infiltration and melanin incontinence. In addition to the literature, lymphocytic vasculitis was found in two cases in our study. However, more cases and studies are needed to assess whether vasculitis is a cause or consequence of the disease.