'Tin-tack' sign in localized pemphigus foliaceus.

Two patients with localized pemphigus foliaceus are described, in whom a positive 'tin-tack' sign was a significant feature; this is the appearance of small horny plugs attached to the undersurface of the scale removed from the affected site. This report is intended as a reminder that a positive 'tin-tack' sign is not exclusively a feature of discoid lupus erythematosus but is also seen in localized pemphigus foliaceus.