Pruritus

Presentation

Generalised pruritus

May occur without any underlying skin disease. Xerosis/dry skin in the elderly is one of the commonest caused of itch.

In the absence of overt skin disease consider an underlying diagnosis  such as:

  • Diabetes mellitus
  • Anaemia / Iron deficiency
  • Thyroid dysfunction
  • Liver disease
  • Medication induced (ie opiates)

Rarely:

  • Haematological malignancy eg Lymphoma
  • Other malignancies
  • Psychogenic itch
  • HIV

Vulval and perianal pruritus

Consider the following diagnoses:

  • Candidiasis
  • Dermatophyte infection
  • Irritant dermatitis or allergic contact dermatitis
  • Lichen simplex
  • Lichen sclerosis
  • Infestation with thread worms
  • Intra-epithelial neoplasia — ask about previous history of anogenital warts or cervical intra-epithelial neoplasm
Management

Generalised pruritus
Treat any underlying disease
Regular emollient and soap substitutes
Oral antihistamines (sedating type may be more helpful in itch)
Consider menthol in aqueous cream (0.5%- 2%)

 

Investigations as appropriate

  • Glucose
  • Renal Function
  • Full blood count
  • Ferritin
  • Liver Function tests
  • Thyroid Function tests
  • Medication review

 

If indicated by history

  • Chest x-ray
  • Abdominal ultrasound
  • HIV test

Vulval and perianal pruritus
Investigations as appropriate

  • Urinalysis for glycosuria
  • Swab for yeasts
  • Stool sample for ova and parasites

Management

  • Emollients, soap substitutes and avoidance of irritants
  • Treat the underlying disease where applicable
  • Mild / moderate steroid plus antifungal / antibacterial
  • Potent topical steroid may be required for limited period in lichen simplex and lichen sclerosis
Referral

Dermatology Referral Criteria

Generalised pruritus

  • Unresponsive to management
  • Diagnostic uncertainty

Vulval and perianal pruritus

  • Diagnosis uncertainty
  • Uncontrolled symptoms
  • If contact allergy suspected
Patient Information