General Hx:

Chronic/acute, intensity, sleep disturbances, concomitant disease, drugs history, social history, occupational history, travel, close contacts, sexual history

Differentials:

Severe pruritis:

• Scabies

• urticaria

• eczema

• insect bites

• dematitis herpatiformis

• lichen planus

• Generalised itching (renal, liver, haematological)

  

Acute skin rashes:

• Erythroderma
• dermatitis (contact, atopic seborrheic)
• drug eruptions
• TEN
• Stevens-Johnsons syndrome
• urticarial
• Infective (e.g. herpes, varicella, impetigo)
• purpuric (meningococcal, septic emboli)

Chronic skin rashes:

• acne vulgaris
• lichen planus
• eczema
• psoriasis
• sebhorrheic warts
• infective - fungal (tinea versicolor, Trichophyton - athletes foot)