Introduction

Headaches are not uncommon for many people, and usually easily fixable by taking one or two capsules of paracetamol or ibuprofen. However, headaches can be triggered by a range of factors leading it to have a complex aetiology. In some circumstances, they can grievously affect our quality of life. New daily persistent headache (NDPH) falls under a new category of headache disorders that was initially described in 1986, which can be highly disabling to the individuals affected.1 They are unique as the symptoms remain persistent from onset. As studies go on, NDPH is classified as probably the most difficult primary headache to treat. This article will describe the current knowledge, clinical features, diagnosis, trigger factors, epidemiology, and therapeutic options of NDPH. 

Characteristics and diagnosis

 A brief overview of the typical features of NDPH

A new daily persistent headache (NDPH) comes on suddenly and continues without remission for a period of at least 24 hours. The headache begins acutely and reaches its peak within 3 days.2 The clinical characteristics vary considerably. Pain usually occurs on both sides of your head and is often accompanied by constraint and oppressing sensations. A significant proportion of NDPH patients could recall the exact onset of the headache after many years of suffering. Despite continuous treatment, the headache persisted for decades. NDPH shares features with other chronic daily headaches (CDH), for example, they share features with both migraine and standard tension headaches.

There are two main forms of NDPH:

• Primary NDPH: they generally occur in a person who does not have a history of headaches. Healthcare professionals often call this “idiopathic”. Thecause of primary NDPH is not fully understood.
• Secondary NDPH: they can be triggered by certain events, such as viral illnesses or the alteration of cerebrospinal fluid (CSF) pressure and volume. Mental health conditions have also been suggested to be linked to NDPH, although there was not enough direct evidence to support this proposal.

Children, adolescents, and adults can all be affected by NDPH. However, according to a study of chronic headache conducted in Norway, the average age of onset is 35 years. The same study found that NDPH appears to be more prevalent in individuals assigned female at birth.³

How to clinically diagnose NDPH?

The newest ICHD – 3 Beta: IHS Classification has clearly outlined the diagnosis criteria:⁴

• Persistent headache fulfilling criteria B and C
• Distinct and clearly-remembered onset, with pain becoming continuous and unremitting within at least 24 hours
• Present for more than 3 months
• Not better accounted for by another ICHD-3 diagnosis

Nevertheless, if the symptoms are present for less than 3 months, and it does not match with other headache disorder criteria, a health expert might still consider it as new daily persistent headache.

How many subtypes of NDPH exist?

New daily persistent headache currently has two known subtypes:

• A self-limiting subtype: also referred to as the lucky one, which typically resolves within several months without requiring therapy. 
• A refractory subtype: this usually happens on secondary NDPH patients that are resistant to aggressive treatment regimens.

The causes and triggers of NDPH

The pathogenesis of NDPH is still unclear, but the experts suspect the triggers could be certain events, such as brain injury, viral infections, or mental health disorders, for example depression or anxiety. A person who stays in long-time pressure situations is also more likely to develop NDPH than others. 

The most common trigger of NDPH is having an infection, especially dominated by a virus, which includes:

• Epstein-Barr virus (a member of the herpes virus family, commonly happens among teenagers and young adults)
• Herpes Simplex Virus (HSV-1 is known as fever blister or cold sores; HSV-2 usually happens on private parts)
• Cytomegalovirus (CMV is common among infant, they can cause chickenpox)
• COVID-19 (A literature review shows COVID-19 may trigger NDPH)⁵

Another growing view in the field is that NDPH is related to irritation and inflammatory factors of the central nervous system.⁶ Particularly, the increase of tumour necrosis factor alpha(TNF-a) in the cerebrospinal fluid leads to a raise of calcitonin gene-related peptide (CGRP) in the brain, and CGRP sensitises peripheral nerves and had a positive correlation in pains.⁷ 

Treatment Options for NDPH in health professionals

At present, there is no specific therapy or clinical guidelines for NDPH. In clinical practice, healthcare professionals usually manage NDPH with conventional drugs for migraine.⁸ However, no significant evidence could prove the efficacy. There are different types of therapeutic approaches for treating NDPH and neuropathic pains:⁹

Anti-inflammation: Methylprednisolone

Anti-depressant : Amitriptyline, venlafaxine, nortriptyline

Anticonvulsant / anxiolytic, gabapentin, pregabalin, topiramate

Anaesthetic (nerve blocking): Lidocaine

 Safety measures and cautions when using medication for NDPH:

The medication used to manage NDPH may cause serious adverse events, and should not overuse than recommend does. They usually require a period of adaptation, but if they make you feel strongly uncomfortable, and before you stop or change the medication, always consult with your General Practitioner (GP) or health experts first. There is another thing to be aware of: It is not a good idea to borrow these types of medicines from others.

Coping Strategies for NDPH

Coping with NDPH could significantly reduce your quality of life. Many of the headache disorders that fall under this category need specific treatments. Do not panic if you have been diagnosed with NDPH, as they can be self-recovering. A strong immune system can help you fight off infections and diseases. Try to put those things that stress you away, 

Keep a good mood and balance your diets, a healthier lifestyle may be the key cure.

FAQs

What is the difference between NDPH and other chronic headaches?

The major distinction between these two is that NDPH is new, happening without headache history, and the patients could remember the exact onset of headache. The pains usually occur on both sides of the head, sustaining and persisting without any improvement within the first 24 hours.

What is the difference between primary headache and secondary headache?

A primary headache disorder has unknown underlying triggers, and could be caused by stressful, anxious, hormonal changes, and a drop in body resistance. A secondary headache disorder is a result of another disease that likely causes inflammation of the central nervous system. Medication overuse is also a main cause of secondary headache disorders. 

If I cannot manage to book a slot with my GP and I suspect I have NDPH, what should I do?

In this case, you should go to the Acute and Emergency Department or a walk-in clinic as soon as possible. Watch out if you have symptoms such as, dizzy, nausea and fever, or your blood pressure is higher than standard levels, some conditions for example cerebral haemorrhage , meningitis also cause sudden and persistent headaches. 

If my friends have a headache, can I lend my medication to them?

It depends; you can provide them with the medicine if they ask for it and if it is available over-the-counter, such as ibuprofen or paracetamol. Those people can also access them over the counter in the supermarket. Those are also called first-line medicines for headaches. Usually, the therapy for managing NDPH is prescribed with strong interference of the neural network, which means if using it in an inappropriate way serious side effects may occur. In this case, you should not borrow any medication for treating NDPH from anyone. Also, keep those medicines away from your children. After all, if they really suffer from a heavy headache and the first-line medicines are not effective, the best thing you can do is to take them to their GP or A&E department.

Summary

Although the causes of NDPH remain mystical and difficult to accurately diagnose, it usually resolves within a few months without treatment. Although the refractory subtype is rare, the persistent pains could cause a significant inconvenience and a poor quality of life. A persistent headache is not a small deal, no matter whether it is NDPH or any other chronic headaches. It is therefore recommended that if your headache has not disappeared or has not improved after 24 hours after taking common painkillers, consult a pharmacist or your GP.