Videomicroscopy in alopecia areata.

Background. Diagnosis of alopecia areata is generally made on clinical examination alone. However, diagnosis may be difficult, particularly in the diffuse forms. Videomicroscopy is a recently developed non-invasive technique that has been little studied in the diagnosis of alopecia. In a preliminary study, we attempted to describe the semiological appearance at videomicroscopy and its diagnostic value for alopecia areata. Patients and methods. Forty patients with confirmed diagnosis of alopecia were successively studied by video microscopy: alopecia areata (18 cases), androgenogenetic alopecia (7 cases), pseudo alopecia areata (7 cases), telegenic effluvium (4 cases), folliculitis decalvans (3 cases) and lupus discoides (1 case). Patients with types of alopecia other than alopecia areata were studied as controls. The video microscopic examination was carried out on the centre and area surrounding the plaques of alopecia. The images were recorded and reviewed retrospectively. The semiological appearance of the scalp and hair was noted. Results. Various types of semiological appearance were observed in alopecia areata: yellowish or erythematous macules centred around the ostium, short exclamation mark hairs, a white down or persistent white hair, pustules with a whitish keratin plug in the ostium and depigmentation of the shaft of the terminal hairs. However, in patients with alopecia areata there was none of the predominantly squamous, inflammatory or atrophied appearance seen in pseudo-alopecia areata or lupus discoides, folliculitis (folliculitis decalvans) or shrinkage of the hair shafts (androgenogenetic alopecia). Discussion. Videomicroscopy allows a detailed semiological description of damage to the scalp. in the majority of patients with alopecia areata, the yellowish ring was centred around the ostium. A knowledge of the appearance of this finding is helpful in diagnosing diffuse forms of alopecia areata or forms likely to be confused with pseudo alopecia areata. It would perhaps be of value to investigate for a correlation between the semiological appearances noted in our study and the progression and prognosis of alopecia areata.