It is a clinician-administered questionnaire consisting of 10 items. Seven items related to pain quality (i.e. sensory and pain descriptors) are based on an interview with the patient and 3 items based on the clinical examination.  The DN4 (which stands for Douleur Neuropathique 4) is one of the questionnaires that can be useful in diagnosing neuropathic pain. It has components of how the pain feels to the patient but also requires the examining health professional to assess whether there is reduced sensation (hypoaesthesia) to touch or pinprick and whether light brushing increases or causes pain (allodynia). Questionnaire initially written in French but immediately translated into English by the same team. The scale has been widely used since 2005 because of its simplicity. It evaluates neuropathic pain following central and peripheral neurological lesions.It is also used for diagnostic purposes, allowing the clinician to determine if the pain is of neuropathic origin.
This questionnaire has been well validated in a number of studies.
The DN4 questionnaire was originally developed and validated in French.
It is a reliable component of the diagnostic work up for painful diabetic polyneuropathy
Inter-rater agreement coefficient:0.80 (0.71–0.89), and test-retest intra-class correlation coefficient: 0.95 (0.92–0.97)].
The Persian version of DN4 questionnaire is a reliable, valid, feasible, and easily administered tool for precise discrimination neuropathic pain from NNP in Farsi. The characteristics of this test can assist practitioner to diagnose neuropathic pain accurately for both clinical and research purposes.
The DN4 is an easy-to-use screening tool that is reliable for discriminating between neuropathic and nociceptive pain conditions in daily practice. 
Valid for a cut-off value ≥ 4 points 
DN4 is valid for painful diabetic polyneuropathy which supports its usefulness as a screening tool for neuropathic pain in diabetes.
The DN4 questionnaire has very good sensitivity (83%) 
It has specificity of (90%) 
- Validation of DN4 as a screening tool for neuropathic pain in painful diabetic polyneuropathy.fckLRSpallone V1, Morganti R, D'Amato C, Greco C, Cacciotti L, Marfia GA.
- Validity and reliability of the persian (Farsi) version of the DN4 (Douleur Neuropathique 4 Questions) questionnaire for differential diagnosis of neuropathic from non-neuropathic pains.fckLRMadani SP1, Fateh HR, Forogh B, Fereshtehnejad SM, Ahadi T, Ghaboussi P, Bouhassira D, Raissi GR.
- Validation of the Dutch version of the DN4 diagnostic questionnaire for neuropathic pain.fckLRvan Seventer R1, Vos C, Giezeman M, Meerding WJ, Arnould B, Regnault A, van Eerd M, Martin C, Huygen F.