Q: What is pruritus? I have been suffering from it since the past four months. There is skin irritation, prickling and stinging. When I wear pants it really bothers me. I have gabapentin 300 mg and paroxetine 20 mg. Do you think this could help me since I am very frustrated. All my blood tests are normal. I smoke but plan to quit soon as I think this could be a factor in causing anxiety and panic making my legs burn and itch. I am afraid to wear clothes as it makes me crazy with the itch. Do I need to do any test?

A:Itching (pruritus) has a number of causes. They can be as follow: 1. Dermatological disorders 2. Systemic diseases 3. Psychogenic pruritus 4. Iatrogenic pruritus Dermatological disorders: common dermatoses known to produce pruritus are scabies, pediculosis, insect bites, eczema (Fig. 15.1), urticaria, prickly heat, lichen planus, dermatitis herpetiformis, bullous pemphigoid, psoriasis, seborrhoeic dermatitis, dermatophytosis (tinea), urticaria pigmentosa, etc. Systemic disorders: 1. Endocrine - diabetes mellitus, myxoedema, hyperthyroidism, hypoparathyroidism. 2. Hepatic - intrahepatic and extrahepatic biliary obstruction (cholestasis). 3. Renal - chronic renal insufficiency 4. Blood diseases (Hematological) - iron deficiency anaemia, polycythemia, leukaemia, Hodgkin?s lymphoma, mycosis fungoides, mast cell disorders. 5. Intestinal parasites - infestation with hookworm, round worm, pinworm. 6. Collagen vascular disorders - SLE, sicca syndrome. 7. Neurological - multiple sclerosis, brain tumour. 8. Pregnancy Psychogenic pruritus: Psychosomatic disorders resulting in itch commonly occur in the middle aged or older individuals. Iatrogenic pruritus: Commonly induced by opium alkaloids, CNS stimulants, antidepressants, and belladona alkaloids. So your itch can be due to any one of the causes. Consult a dermatologist and get proper treatment. History and clinical examination is of paramount importance. In addition, investigations outlined below may be undertaken to find the underlying cause. 1. Haemogram including ESR 2. Liver function tests 3. Kidney function tests 4. Urine examination for albumin, sugar and cells 5. Blood sugar 6. Stool examination for blood, worms and ova 7. Chest X-ray 8. Thyroid function tests 9. Uric acid estimation and also acid phosphatases.