Mitsuyoshi Omoto

Density and fine structure of peripheral nerves in various skin lesions of atopic dermatitis

The density and fine structure of the peripheral nerve system in various skin lesions of 64 patients with atopic dermatitis (AD) was quantitatively analyzed by immunohistochemical staining with antibodies directed against protein gene product (PGP) and substance P (SP). The density of PGP-positive peripheral nerves was 2.5 × 103μm2/Δs (Δs = 0.24 mm2 selected area) in early acute lesions, 3.8 × 103μm2/Δs in subacute lesions, 4.9 × 103μm2/Δs in lichenified lesions and 7.1 × 103μm2/Δs in prurigo lesions of AD. The density of nerve fibers in subacute, lichenified and prurigo lesions was significantly higher than in uninvolved skin of AD patients (2.0 × 103μm2/Δs). Electron microscopically, bulging of axons with many mitochondria and a loss of their surrounding sheath of Schwann cells suggests that the free nerve endings in skin lesions of AD are in an active state of excitation. Many pinocytotic vesicles in the periphery of basal keratinocytes facing nerve endings which contained many neurovesicles suggests reciprocal effects between keratinocytes and nerve endings. The number of SP-positive nerve fibers in AD lesions was far less than one-tenth of the number of PGP-positive nerve fibers.

Histopathological Features of Recalcitrant Erythema of the Face in Adult Patients with Atopic Dermatitis

Recalcitrant erythema on the face of 21 adult patients with atopic dermatitis was histologically examined. All patients had been applying topical corticosteroids to the facial erythema for three years or more.