Possible involvement of neuropeptidergic sensory nerves in alopecia areata.
Alopecia areata (AA) is a dermatosis involving the sudden occurrence of bald patches on the scalp. Although the aetiology is unknown, experimental data indicate that cutaneous microcirculation plays an important role. The skin is richly innervated by neuropeptidergic sensory nerves that help regulate microvascular circulation. This study shows a reduction of cutaneous levels of substance P and calcitonin gene-related peptide (CGRP) but not of vasoactive intestinal polypeptide in scalp biopsies from patients with AA. Laser-Doppler flowmetry was used to study microcirculation of the scalp. Results indicate that patients with AA have lower basal blood flow and greater vasodilatation following intradermal CGRP injection than control subjects. A vascular hyper-reactivity to vasodilatatory substances such as neuropeptides, probably because of the lack of these substances, is hypothesized.
Rossi
R
R
Institute of Clinical Dermatology, University of Florence, Italy.
Del Bianco
E
E
Isolani
D
D
Baccari
M C
MC
Cappugi
P
P
D000293:Adolescent; D000328:Adult; D000506:Alopecia Areata / Q000503:physiopathology*; D001706:Biopsy; D015740:Calcitonin Gene-Related Peptide / Q000032:analysis / Q000494:pharmacology; D016022:Case-Control Studies; D006801:Humans; D007279:Injections, Subcutaneous; D017078:Laser-Doppler Flowmetry; D008833:Microcirculation / Q000187:drug effects; D008875:Middle Aged; D009475:Neurons, Afferent / Q000502:physiology*; D009479:Neuropeptides / Q000502:physiology*; D011863:Radioimmunoassay; D012535:Scalp / Q000098:blood supply* / Q000473:pathology; D012678:Sensation Disorders / Q000503:physiopathology*; D013373:Substance P / Q000032:analysis; D014660:Vasoactive Intestinal Peptide / Q000032:analysis
D009479:Neuropeptides; D013373:Substance P; D014660:Vasoactive Intestinal Peptide; D015740:Calcitonin Gene-Related Peptide