Patients with erythematous Ixodes tick-borne relapsing fever were examined and their skin biopsy specimens were morphologically studied to reveal clinical, immunological and morphological features of erythematous Ixodes tick-borne relapsing fever. Two types of development of erythema migrans were identified. These include 1) a typical type that appears as an area of homogenous hyperemia or that of annular shape and 2) an atypical one that presents as minor vesicles. There were elevated serum immunoglobulins A levels at the height of the
disease. Morphologically, at the early stage of the
disease, the center of erythema shows disturbances characterized by epidermal dystrophic processes, koilocytosis, subhorny and epidermal vesicles. The dermis displays solid perivascular lymphocytic infiltrates admixed with fibroblasts, fibrocytes, macrophages, plasmocytes, eosinophils, degranulated labrocytes. The interstitium exhibits scanty infiltrates. These changes are less pronounced at the periphery. Electron microscopy shows the structures morphologically similar to those of Borrelia. The late stage (days 15-23) of the
disease is marked by insignificant dystrophy and perivascular fibrosis. There were no interstitial infiltrates. By and large, the pattern of clinical and immunological manifestations in patients with erythema migrans correlates with dermal morphological changes.