Yes. Itching is commonly a conspicuous symptom, although at times pricking, stinging or a feeling of burning constitutes the chief sensation. #In what way may the eruption be atypical?# Exceptionally the wheals, or lesions, are peculiar as to formation, or another condition or disease may be associated, hence the varieties known as urticaria papulosa, urticaria haemorrhagica, urticaria tuberosa, and urticaria bullosa. #Describe urticaria papulosa.# Urticaria papulosa (formerly called _lichen urticatus_) is a variety in which the lesions are small and papular, developing usually out of the ordinary wheals. They appear as a rule suddenly, rarely in great numbers, are scattered, and after a few hours or, more commonly, days gradually disappear. The itching is intense, and in consequence their apices are excoriated. Sometimes the papules are capped with a small vesicle (vesicular urticaria). It is seen more particularly in ill-cared for and badly-nourished young children. #Describe urticaria haemorrhagica.# Urticaria haemorrhagica is characterized by lesions similar to ordinary wheals, except that they are somewhat hemorrhagic, partaking, in fact, of the nature of both urticaria and purpura. #Describe urticaria tuberosa.# In urticaria tuberosa the lesions, instead of being pea- or bean-sized, as in typical urticaria, are large and node-like (also called _giant urticaria_). #What is acute-circumscribed [oe]dema?# In rare instances there occurs, along with the ordinary lesions of the disease or as its sole manifestation, sudden and evanescent swelling of the eyelids, ears, lips, tongue, hands, fingers, or feet (_urticaria [oe]dematosa_, _acute_ _circumscribed [oe]dema_, _angioneurotic [oe]dema_). One or several of these parts only may be affected at the one attack; in recurrences, so usual in this variety, the same or other parts may exhibit the manifestation. (These [oe]dematous swellings occurring alone might be looked upon, as they are by most observers, as an independent affection, but its close relationship to ordinary urticaria is often evident.) #Describe urticaria bullosa.# Urticaria bullosa is a variety in which the inflammatory action has been sufficiently great to give rise to fluid exudation, the wheals resulting in the formation of blebs. #What is the etiology of urticaria?#