Other causes of subcorneal and intraepidermal blistering
This is a common cause of blistering in children. The bullae are flaccid, often contain pus and are frequently grouped or located in body folds. Bullous impetigo is caused by Staphylococcus aureus.
A toxin elaborated by some strains of S. aureus makes the skin painful and red; later it peels like a scald. The staphylococcus is usually hidden (e.g. conjunctiva, throat, wound, furuncle).
Here sweat accumulates under the stratum corneum leading to the development of multitudes of uniformly spaced vesicles without underlying redness. Often this occurs after a fever or heavy exertion. The vesicles look like droplets of water lying on the surface, but the skin is dry to the touch. The disorder is self-limiting and needs no treatment.
As its name implies, the lesions are small groups of pustules rather than vesicles. However, the pustules pout out of the skin in a way that suggests they were once vesicles (like the vesico-pustules of chickenpox).
The cause of this rare disease is unknown, but oral dapsone usually suppresses it.
Severe acute eczema, especially of the contact allergic type, can be bullous. Plants such as poison ivy, poison oak or primula are common causes. The varied size of the vesicles, their close grouping, their asymmetry, their odd configurations (e.g. linear, square, rectilinear) and a history of contact with plants are helpful guides to the diagnosis.
In pompholyx, highly itchy small eczematous vesicles occur along the sides of the fingers, and sometimes also on the palms and soles. Some call it ‘dyshidrotic eczema’, but the vesicles are not related to sweating or sweat ducts. The disorder is very common, but its cause is not known.
Some viruses create blisters in the skin by destroying epithelial cells. The vesicles of herpes simplex and zoster are the most common examples.
Itchy vesicles appear on the sun-damaged skin of the trunk, usually of middle-aged males. The cause is not known and the condition can be persistentadespite its name.