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Thursday 11 February 2021

bullous impetigo



- pustuleis filled with neutrophils
- cleavage plane is subcorneal or upper granular layer
- variable acantholysis

  • neutrophils may be seen in the spongiotic stratum spinosum

- bacterial clusters are evident with Gram stain
- dermal infiltrate

  • The underlying dermal infiltrate contains a mixed neutrophil and lymphocytes infiltrate

Differential diagnosis

- allergic contact dermatitis: different clinical history, extensive spongiosis, numerous eosinophils
- pemphigus

  • Antibodies in a pemphigus like pattern: may be demonstrated in bullous impetigo and distinction from pemphigus foliaceous may therefore be a problem; generally the presence of numerous neutrophils and the recognition of Gram positive cocci is sufficiently characteristic of impetigo, as acantholytic cells are very scanty

- herpes simplex infection: different clinical history, viral inclusions
- insect bites: different clinical history
- Other blistering disorders: including chronic bullous dermatosis of childhood
- subcorneal pustular dermatosis and pustular psoriasis
- superficial variant of pemphigus: particularly as the latter become secondarily infected and there may be one or two acantholytic cells in impetigo
- thermal burns: different clinical history

See also

- bullous diseases