History: Psoriasis of the fingertips and nails can be like this where the conventional morphology of psoriasis is shown and involvement of the posterior  nail fold  causes nail dystrophy.However localised pustular psoriasis of the fingertips and nails can also occur.Here you tend to get onycholysis with loss of the nails and sterile pustules around the fingertips.This is sometimes known as acrodermatitis continua of Hallopeau.