Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Essential Dermatology for GPs The Itchy Patient Lucy Scriven • Itching may be due to an underlying skin condition – Eczemas – Scabies, lice, threadworms – Psoriasis (sometimes) – Insect bites – Exanthems – Lichen planus – Nodular prurigo – Bullous pemphigoid – Polymorphic light eruption What’s this? • Pompholyx • PLE • Bullous pemphigoid • Eczema • Lichen planus • Psoriasis • Scabies • Papular urticaria What if they are just itchy? Pruritus = Itchy skin in the absence of any obvious dermatological condition Generalised Pruritus Localised Pruritus • Medications • Dermatological conditions with subtle signs • Systemic disease • Psychogenic • Aquagenic pruritus • Idiopathic • Brachioradial pruritus • Notalgia paraesthetica • Up to 50% of pts will have no clear cause – idiopathic pruritus • This should be a diagnosis of exclusion! • So – we need a logical approach to try to ascertain a cause....... STEP 1: TAKE A CAREFUL HISTORY • Onset, duration, pattern, effect on sleep, past history of skin disease, contacts, response to treatments so far • Medications – Opioids, Statins, ACEI, Digoxin – Need to discontinue suspected drug for a few weeks if possible • Systemic disease – Liver disease, renal failure, haematological disorders, thyroid disease, paraneoplastic • Localised Pruritus – 2 conditions which cause localised areas of itching / burning – Brachioradial pruritus - around elbow and extensor surface of forearm – Notalgia paraesthetica – mid-scapular area – Consider capsaicin cream thinly od increased to maximum qds over 2wks. Treat for 8 wks Or try gabapentin or low dose amitriptyline. • Aquagenic pruritus – Patients complain of intense pricking itch on contact with water or change of skin temperature – Do not develop a rash – Responds poorly to antihistamines – May respond to phototherapy STEP 2: EXAMINE THE PATIENT CLOSELY – Dry skin / asteototic eczema • Common cause, especially in the elderly in winter • Signs may be subtle • FEEL the skin! • Look closely for fine scale – Excoriations – Bruising – Lichen simplex chronicus • Asteototic eczema • Excoriations • ‘Butterfly’ distribution • Lichen simplex chronicus • Dermographic urticaria – Should be reproducible STEP 3 - ? SYSTEMIC DISEASE – Liver disease, renal failure, haematological disorders (e.g. Iron deficiency anaemia, polycythaemia, Hodgkin’s lymphoma), thyroid disease, paraneoplastic phenomena, pregnancy – Thorough history and examination to include checking for enlarged lymph nodes and hepatosplenomegaly • Screening investigations in pruritus – Full blood count – Ferritin – CRP – Routine biochemistry (U&E, LFT, bone, glucose) – Thyroid function – Antimitochondrial antibody (1 biliary cirrhosis) – Urinalysis – Chest X ray – Consider immunoglobulins and plasma electrophoresis in older pts STEP 4 - ? PSYCHOGENIC – Anxiety / depression can cause or be caused by pruritus, esp in older pts – Delusions of parasitosis • Patient is convinced that a parasite / infestation is living in their skin • May bring inorganic matter to the consultation • Excoriations often seen but nothing else – no burrows, no urticated papules • Idiopathic Pruritus – No identifiable cause found in up to 50% pts – Can cause persistent and widespread itching and often extensive excoriation – Common in 7th decade and beyond Management • Treat any underlying cause • Provide a patient information leaflet • General measures – Liberal emollients if at all dry – keep in fridge – Sedating antihistamines e.g. Hydroxyzine 25-50mg nocte +/- 10mg tds through the day if required. Use periodically as tolerance may develop – Topical agents e.g. 1 or 2% menthol in Aqueous cream, Eurax cream, Balneum Plus / Dermol – Phototherapy may help in recalcitrant cases • Manage any features of anxiety or depression – Consider low dose amitriptyline (25-75mg nocte) • If associated with hepatic or renal disease or malignancy – Can be difficult to treat – Naltrexone and rifampicin have been reported as helpful in renal disease – Cholestyramine can be effective if secondary to liver disease • Avoid aggravating factors • Reduce damage from scratching