Clinical management of the painful diabetic neuropathies.

The neuropathies of diabetes are common, affecting up to 50% of older patients with type 2 diabetes. They have been the subject of several recent reviews 1‐3 . Only a minority of patients experience neuropathic symptoms, so the absence of symptoms must never be equated with the absence of neuropathy 1‐3 . A careful clinical examination of the lower limbs and feet is essential to diagnose neuropathy in any diabetic patient. Pain and diabetic neuropathy Pain is a subjective symptom that often motivates patients to seek medical advice. It may be present in several of the somatic neuropathies of diabetes. Two main types of pain have been described. i Superficial or dysaesthetic pain is typically experienced by patients with sensory neuropathies. It is unfamiliar to the patient, who often describes it as burning, shooting, tingling, stabbing or lancinating, or likens it to hot needles or repeated electrical shocks. It is difficult to localise, intermittent and prone to nocturnal exacerbation, with allodynia and bedclothes’ hyperaesthesiae. It is thought to be caused by erratic increased firing of sprouting nociceptive fibres. i In contrast, nerve trunk pain is more familiar to the patient, and is described as aching, tender and occasionally knife-like. It may be experienced in spinal root compression or nerve entrapment syndromes. Painful neuropathies A number of the diabetic neuropathies may give rise to painful symptoms which may be present at any time during the evolution of the condition (Table 1).