Causes and diagnosis of blistering skin conditions

Blisters occur when fluid accumulates in the skin following damage to the epidermis, dermo-epidermal junction or the upper dermis. Blisters are usually superficial and short-lived, and most commonly form in response to a specific injury, although blistering skin can also be caused by autoimmune conditions. See Causes of blistering skin conditions for causes of blistering skin conditions. Some more common autoimmune blistering skin conditions include bullous pemphigoid, dermatitis herpetiformis, pemphigus, pemphigoid gestationis, acquired epidermolysis bullosa (EBA) and linear IgA disease.

Table 1. Causes of blistering skin conditions
Common	Uncommon	Rare
bullous impetigo insect bites contact dermatitis burns pompholyx herpes simplex virus varicella zoster virus erythema toxicum	bullous pemphigoid dermatitis herpetiformis bullous erythema multiforme porphyria cutanea tarda fixed drug eruption bullae of kidney failure peripheral oedema transient neonatal pustular melanosis infantile acropustulosis	epidermolysis bullosa (inherited or acquired) linear IgA disease pemphigus cicatricial pemphigoid toxic epidermal necrolysis Stevens–Johnson syndrome staphylococcal scalded skin syndrome diabetic bullae Hailey–Hailey disease pemphigoid gestationis mastocytosis (including mastocytoma)

Blistering skin conditions should be diagnosed and managed in consultation with a dermatologist.

Obtain a detailed history and perform a physical examination; excluding autoimmune causes of blisters can help assessment. Obtain a formalin-fixed sample for histology and a fresh sample in transport medium for direct immunofluorescence. Direct immunofluorescence is a time-sensitive test—seek advice from a specialist (eg over the phone) on appropriate sampling technique and specimen preparation if required. In addition to biopsies, testing for serum skin antibodies can help diagnosis and is becoming increasingly available for various conditions.