This study is designed to evaluate the topical Citrullus colocynthis fruit oil efficacy in treatment of painful peripheral diabetic neuropathy (PDN) in a randomized double blind placebo-controlled clinical trial design. This study includes 60 patients from SUMS endocrinology and diabetes clinic. Patients with painful conditions other than PDN such as radiculopathies will be excluded. After giving the Informed consent the patients will be underwent NCS (Nerve Conduction Study) for confirming the diagnosis before recruitment. They will be followed for 12 weeks and after 12 weeks the outcome measures including Neuropathic Pain Scale (NPS), WHOQOL-BREF (World Health Organisation Quality of Life Brief) questionnaire and electrodiagnostic criteria will be evaluated.

Inclusion criteria:

• Controlled type 1 or 2 diabetes mellitus
• Painful Peripheral diabetic neuropathy for more than 3 months
• Age more than 18 years old
• Patients consent on enrolling study and admitting study protocol

Exclusion criteria:

• Other causes of pain in lower extremities like lumbar disk herniation
• Ulcerative lesions in lower extremities
• Dermatitis
• Pregnancy
• Lactation
• Citrullus colocynthis allergy
• Unstable cardiac, neurological or renal disease
• Diagnosed other types of neuropathy