Clinical images - Diagnosing a blistering rash

Use these pictures to differentiate shingles, pemphigus, pemphigoid and insect bite rashes. By Dr Nigel Stollery

Shingles

Presentation

  • Can occur at any age in patients who have had varicella
  • Vesicular eruption affecting whole or part of a single dermatome
  • Pain often precedes rash formation
  • Pain may last long after rash clears (post-herpetic neuralgia)
  • Further episodes may occur
  • In those who are not immune, varicella may develop after contact with shingles

Management

  • In young, fit patients, analgesia may be all that is required
  • Antiviral treatment, such as aciclovir, can be helpful


Bullous pemphigoid

Presentation

  • Usually occurs in the elderly
  • Blisters are tense and may be blood filled
  • Often affects flexures
  • Oral blisters may occur but are rare
  • Patients usually otherwise well
  • Nikolsky's sign (when rubbing results in exfoliation of top layer of skin) is negative

Management

  • Treatment includes oral steroids and immunosuppressant drugs
  • Dose can often be reduced quite quickly
  • Usually settles with time and treatment can be stopped

 



Bullous pemphigus

Presentation

  • Usually occurs in middle age
  • Affects trunk, flexures and scalp
  • Occurs in those with otherwise poor health
  • May be associated with malignancy, including undiagnosed tumours
  • Blisters are superficial and flaccid
  • Severe, often life-threatening condition
  • Nikolsky's sign is positive

Management

  • Treatment includes oral steroids and immunosuppressant drugs
  • Treatment can be difficult
  • Treatment is usually very prolonged

Insect bite

Presentation

  • Single or multiple vesicles, usually in a cluster
  • Often intensely itchy
  • Urticaria may precede appearance of the vesicle
  • If recurrent, insect repellents may decrease risk of further bites

Management

  • Oral or topical antihistamines will decrease itching
  • Secondary bacterial infection may occur
  • In more severe cases, topical or oral steroids can be helpful
  • Rarely, anaphylaxis may develop (especially to wasp stings)

Dr Stollery is a GP in Kibworth, Leicestershire, and clinical assistant in dermatology at Leicester Royal Infirmary.

Have you registered with us yet?

Register now to enjoy more articles and free email bulletins

Register

Already registered?

Sign in

Before commenting please read our rules for commenting on articles.

If you see a comment you find offensive, you can flag it as inappropriate. In the top right-hand corner of an individual comment, you will see 'flag as inappropriate'. Clicking this prompts us to review the comment. For further information see our rules for commenting on articles.

comments powered by Disqus