1. Itchy rashes Maggie Kirkup SpR Dermatology Royal United Hospital Bath

2. How common is skin disease in the population? 1.Questionnaire - 1217 unselected adults Skin accounted for 25% of 6009 ailments (Market Research Group 1982) 2.Examination - 55% of population had a skin complaint, 22.5% worthy of medical attention 1. 1 Rea et al Br J Prev Soc Med 1976; 30: 107-14

3. Describe itch “local discomfort or irritation of the skin, prompting the sufferer to scratch or rub the affected area. It is the main symptom of skin disease” “a peculiar tingling or uneasy irritation of the skin that causes a desire to scratch the affected area”

4. “It feels as though every nerve ending in my body is attacking me intensely at my ankles, feet, lower legs, neck, under the breasts (even the nipples tingle). It's absolutely horrendous! My hands grow red as a beet and the itching nearly takes the skin off my hands as I scratch.” All Party Parliamentary Report on Impact of Skin Disease. 2003

5. “ It’s like someone tickling you under the skin”

6. Pathophysiology Debate continues over whether there are specific nerve endings for itch Possibly more than one mechanism

7. Pathophysiology of itch Free nerve endings FibrFibres most concentrated in wrists and ankles Unmyelinated C fibres to dorsal horn in spinal cord Scratching is a spinal reflex response Ascends to cerebral cortex via spinothalamic tract Skin inflammation Psychological concerns Chemical mediators Substance P Opioid and non-opioid peptides Somatostatin Neurokinin A Histamine Serotonin Prostaglandins External mediators Environmental heat or dryness

8. Approach to diagnosis of itching History including onset, duration, pattern, effect on sleep, previous skin disease, contacts, other medical problems, drugs, response to treatment so far. Skin examination features of rash, post-inflammatory changes, signs of scratching General examination

9. Signs of itching distress excoriation lichenification shiny nails weals nodules

10. Factors affecting presentation of itchy condition age self-control/ social setting/ distractions other medical conditions/ ability to scratch site of itch specific skin condition duration

11. Causes of itch skin disorders systemic disorders psychogenic habit / itch-scratch cycle physiological?

12. Causes of itch skin disorders systemic disorders psychogenic habit / itch-scratch physiological?

13. Common itchy skin disorders in the young

14. infestations: scabies, lice, threadworms eczemas urticaria psoriasis (sometimes) insect bites – papular urticaria pityriasis rosea viral exanthems

15. Common itchy skin disorders in the young infestations: scabies, lice, threadworms eczemas urticaria psoriasis (sometimes) insect bites – papular urticaria pityriasis rosea viral exanthems

16. Common itchy skin disorders in the young infestations: scabies, lice, threadworms eczemas urticaria psoriasis (sometimes) insect bites – papular urticaria pityriasis rosea viral exanthems

17. Common itchy skin disorders in the young infestations: scabies, lice, threadworms eczemas urticaria psoriasis (sometimes) insect bites – papular urticaria pityriasis rosea viral exanthems

18. Common itchy skin disorders in the young infestations: scabies, lice, threadworms eczemas urticaria psoriasis (sometimes) insect bites – papular urticaria pityriasis rosea viral exanthems

19. Common itchy skin disorders in the young infestations: scabies, lice, threadworms eczemas urticaria psoriasis insect bites – papular urticaria pityriasis rosea viral exanthems

20. Common itchy skin disorders in the young infestations: scabies, lice, threadworms eczemas urticaria psoriasis (sometimes) insect bites – papular urticaria pityriasis rosea viral exanthems

21. Common itchy skin disorders in mature adults

22. infestations: scabies eczemas / nodular prurigo/ xerosis urticaria psoriasis (sometimes) lichen planus bullous pemphigoid polymorphic light eruption

23. Common itchy skin disorders in adults infestations: scabies eczemas / nodular prurigo/ xerosis urticaria psoriasis (sometimes) lichen planus bullous pemphigoid polymorphic light eruption

24. Common itchy skin disorders in adults infestations: scabies eczemas / nodular prurigo/ xerosis urticaria psoriasis (sometimes) lichen planus bullous pemphigoid polymorphic light eruption

25. Common itchy skin disorders in adults infestations: scabies eczemas /nodular prurigo/ xerosis urticaria psoriasis (sometimes) lichen planus bullous pemphigoid polymorphic light eruption

26. Common itchy skin disorders in adults infestations: scabies eczemas/ nodular prurigo/ xerosis urticaria psoriasis (sometimes) lichen planus bullous pemphigoid polymorphic light eruption

27. Common itchy skin disorders in adults eczemas / nodular prurigo/ xerosis urticaria psoriasis (sometimes) infestations: scabies lichen planus bullous pemphigoid polymorphic light eruption

28. Less common skin complaints which itch dermatitis herpetiformis aquagenic pruritus T cell lymphomas pityriasis rubra pilaris onchocerciasis etc etc

29. Localised itch Anogenital/ pruritus ani: think of threadworms, lichen sclerosis, lice, scabies, contact dermatitis Hands: eczemas, scabies, contact dermatitis

30. Localised itch Anogenital/ pruritus ani: think of threadworms, lichen sclerosis, lice, contact dermatitis Hands: eczemas, scabies, contact dermatitis

31. Localised itch Flexures: atopic/ seborrhoeic eczema, scabies Scalp: lice, seborrhoeic dermatitis, psoriasis Any area: discoid eczema, lichen simplex chronicus, contact dermatitis

32. Less common causes of localised itch brachioradial pruritus notalgia paraesthetica

33. Skin disorders which don’t (usually) itch psoriasis ? acne/ folliculitis vasculitis/purpura erythema multiforme secondary syphilis

34. Causes of itch skin disorders systemic disorders psychogenic habit physiological?

35. Systemic causes of itch liver disease renal failure iron deficiency metabolic: protein, zinc, calcium, vitamin deficiencies thyroid disease

36. Systemic causes of itch (part 2) diabetes malignancies: lymphoma, PRV, leukaemias, myeloma pregnancy neurological drugs

37. Screening investigations in itchy patients with no rash Full blood count Ferritin Renal function Liver function Thyroid function ? Chest X ray

38. Psychogenic itch epidemic forms - hysteria delusional parasitosis habit - itch/scratch cycle

39. Management of itching Treat the cause Treat the itch

40. Management of itching There is no specific drug for itch

41. Management of itching keep looking for a cause avoid aggravating factors temperature, humidity, bedding, clothing reduce damage from scratching clothing, bandaging, cut nails

42. Management of itching topical agents gadgets systemic agents psychological interventions

43. Topical agents emollients antihistamines * - doxepin (Xepin) unknown mechanism - crotamiton (Eurax) calamine counter-irritant - capsaicin, menthol local anaesthetics * paste bandages *Risk sensitization

44. Management of itching topical agents gadgets systemic agents psychological interventions

45. Management of itching topical agents gadgets systemic agents psychological interventions

46. Systemic agents Opiod antagonists Ondansetron Rifampicin Cholestyramine Tricyclic antidepressants Thalidomide Phototherapy Antihistamines ?

47. Management of itching topical agents gadgets systemic agents psychological interventions

48. Psychological and alternative interventions Biofeedback Behaviour therapy* Relaxation techniques Acupuncture Hypnotherapy Homeopathy Self-help groups * Melin I et al Behavioural treatment of scratching in patients with atopic dermatitis. Brit J Dermatol 1986; 115: 467-74

49. Summary Itching can be caused by skin disease, systemic disease, psychogenic factors or idiopathic Management and investigation need to be tailored to the patient’s condition and circumstances