This large group includes those forms of urticaria involving wheals, itchiness and/or angioedema only when triggered by specific physical stimuli. For the most common form of physical urticaria, dermographic urticaria or urticaria factitia, this involves vigorous rubbing or scratching of the skin. All forms of physical urticaria can occur individually, together with one or several other forms of physical urticaria, or in patients with spontaneous urticaria or another form of urticaria. Beyond dermographic urticaria/urticaria factitia, other common forms of physical urticaria include cold urticaria and solar urticaria. Rare physical forms of urticaria are pressure urticaria, x-ray urticaria and heat urticaria.