Introduction

Pertussis is a respiratory infection caused by a bacterium. It is also commonly known as the Whooping cough due to the distinctive ‘whooping’ sound produced during coughing. Sinusitis, however, is an illness caused by inflammation within the sinuses found in your face. Although distinct, the two may be linked together as in some cases pertussis infection may spread and begin to affect the sinuses as well. 

What is Pertussis?

Cause

Pertussis is an infection affecting the upper respiratory tract caused by the bacterium Bordetella pertussis. The bacterium typically has a 7-10 incubation period (time between point of infection and showing symptoms) and is very contagious, commonly transmitted by airborne transmission. This means that infection occurs by coming into contact with contaminated respiratory droplets released when an infected person coughs, sneezes, or even talks.

Symptoms and stages

Pertussis tends to exhibit three stages, which may be characterised by the different symptoms. The first stage tends to be called the catarrhal phase. This phase is when the person is most infectious and lasts one to two weeks. Symptoms commonly associated with this stage include common upper respiratory symptoms such as: fever, cough, and a runny nose. Next, is the paroxysmal phase, which could last up to 10 weeks. It is defined by symptoms like violent, prolonged, and exhausting coughing followed by ‘whooping’ sounds during inhalation, giving the signature whooping cough. Other symptoms like vomiting or fatigue may also occur as a result of the continuous coughing. The final stage is called the convalescent stage, which is the phase of recovery. It is a long-lasting phase, which may be present for a range of time, from weeks to months. The symptoms usually experienced are a residual cough, which may become more severe when triggered by an upper respiratory coinfection or irritants.¹ 

Diagnosis

Pertussis may be diagnosed by a physical examination where the doctor will be able to identify the disease by the symptoms described by the patient as well as by the sound of the cough. The doctor may also do a nasal swab, or a saline flush of the nose and back of the throat to collect a sample. These samples will be sent to a laboratory which will perform diagnostic tests like a culture or rapid polymerase chain reaction to confirm the presence of Bordetella pertussis. The doctor may also request a blood sample to check white cell counts, elevated white blood cell counts indicating infection.² 

Treatment

Pertussis is most commonly treated with antibiotics, which will reduce the bacterial growth. Unfortunately neither antibiotics or cough medicines are able to relieve the cough, which accompanies the infection. 

Complications

Pertussis may cause a range of complications. Some complications may occur due to the violent coughing like fracturing a rib, weight loss, lack of bladder control, and fainting. If the infection spreads or if a co-infection occurs, it may cause more serious illnesses like pneumonia. There is also a possibility of symptoms involving the central nervous system, such as encephalopathy (disease of the brain) and seizures.³ 

What is sinusitis?

Types

Sinusitis is a term used to refer to the inflammation of the tissue inside the sinuses. There are four main types of sinusitis. The first is acute sinusitis, which refers to a sinusitis which lasts less than four weeks and improves with treatment. Another type is subacute where symptoms may last anywhere from four to eight weeks and initially do not improve upon treatment. Next is chronic sinusitis and it is defined by symptoms which last more than eight weeks. The disease may repeat or not respond to treatment properly. Lastly, there is the recurrent phase, which may be diagnosed in those who suffer from three or more occurrences of sinusitis within a single year.⁴ 

Causes

Microorganisms

Bacteria, viruses, and fungi may all cause sinusitis, with viruses being the most common causative agent. Most often, fungal sinusitis occurs during a period of weakening of the immune system and so are less common, but when they do occur, they tend to be the most dangerous out of the three. 

Allergies

Allergens, particularly those which are inhaled, may often trigger the tissues of the sinus to become inflamed. This will also increase the chance of infection establishment due to the blocking of mucus drainage. 

Structural issues

People with a deviated septum or nasal polyps may be more likely to experience sinusitis as they are more susceptible to experience a blockage of their nasal passages, which in turn will lead to less effective drainage. 

Symptoms

Common symptoms of sinusitis include:

• Green or yellow mucus, which may also be quite thick
• Runny and blocked nose
• Postnasal drip
• Bad breath
• Bad taste in the mouth
• Feeling of pressure in the eyes, nose, face, ears, or teeth
• Pain in the teeth or ears
• Fever
• Headache
• Cough
• Fatigue

Diagnosis

Most often, a doctor will diagnose sinusitis based on the symptoms mentioned by the patient. They may also look inside the throat, nose, and ears using an endoscope to look for any inflammation or visible blockage. If a doctor suspects the sinusitis is caused by a microorganism, they may take a nasal swab and send it to a laboratory for diagnostic testing. If they think it is to do with allergies, they may carry out testing to identify the causative allergen. In more serious cases, a doctor may order a computer tomography scan or provide a referral to a ear, nose, and throat specialist, also known as an otolaryngologist. 

Treatment

Treatment depends on the cause of the sinusitis. If the cause is bacterial, the doctor may prescribe antibiotics, and if it's fungal, they may prescribe antifungals. For allergic sinusitis, a doctor may recommend antihistamines or steroid intranasal sprays. In the case of structural causes like a deviated septum, surgery may be offered to fix the structural issue. Otherwise, treatment may involve symptom management such as decongestants, saline rinses, or over-the-counter cold or allergy medications. 

Complications

Sinusitis tends to be a mild condition, which resolves on its own but there is a possibility of infectious agents (bacteria, viruses, fungi) spreading. If they spread, they may cause infection of the bones, brain, or eyes, which would be very dangerous. This complication may be identified by experiencing further symptoms like a fever above 40 degrees Celsius, confusion, stiffness of the neck, vision loss, or seizures.⁵

Pertussis and sinusitis

Shared Symptoms 

An issue with pertussis during the catarrhal phase and sinusitis is that the symptoms are similar and so it may be difficult to distinguish the disease early on, which could lead to misdiagnosis. This may result in the selection of the incorrect type of treatment, which may be quite problematic. This is because pertussis tends to be treated with antibiotics whilst sinusitis is usually left to clear on its own. Therefore, if pertussis is misdiagnosed for sinusitis, antibiotic administration will be delayed, allowing the bacteria more time to grow and spread. However, if sinusitis is misdiagnosed for pertussis and antibiotics are given, this may contribute to the rising issue of antimicrobial resistance as it would unnecessarily expose bacteria to an antibiotic, allowing them to mutate and become resistant.

Secondary Sinusitis Following Pertussis

During the illness, there is a possibility of the pertussis spreading to and entering the sinuses. When it does so it will cause infection of the sinus tissues, leading to inflammation, causing sinusitis. 

Impact on the Immune System

Throughout the pertussis infection, the bacterium is able to impact the immune response mainly through the production of toxins. The bacterial toxins will impair immune cell function, weakening the overall immune response. As the immune response is weakened, the body is no longer as effective in fighting other potential pathogens like it was before, increasing the chance of opportunistic infection or co-infection. For example, it may provide an advantage for the establishment of fungal sinusitis, which usually requires a weakened immune response. It may also increase the chance of other bacterial or viral infection, which could also lead to sinusitis. 

Prevention

Vaccination 

The most effective way to prevent pertussis is by receiving the DTaP vaccine (diphtheria, tetanus, and pertussis). The vaccine is very effective and usually administered to children in five doses. The first being at two months old, then four months old, six months old, 15-18 months old, and finally four to six years old. The administration of a booster is also recommended to adults aged between 19-64 years old, as with time, immunity will wane and so it is key to reestablish the top level of protection.³ 

Preventive Measures for Sinusitis

For sinusitis the most effective preventative measures are dependent on the type of sinusitis someone has. For sinusitis caused by microorganisms, the best prevention strategies involve hand washing with soap and warm water and avoiding direct contact with infected individuals to avoid exposure to potential pathogens. For allergic sinusitis, preventative measures will involve minimising potential allergic reactions by using medications or allergy shots and by avoiding the allergen as much as possible if known. Stopping smoking may also be recommended as smoking may cause weakening of the immune system.⁵ 

Summary 

Pertussis and sinusitis are two different conditions, one caused by a bacterium and the other caused by multiple microorganisms, allergies, or structural issues respectively. Although different, there is some commonality between symptoms, which could lead to misdiagnosis. There is also potential for pertussis infection increasing the chance of developing sinusitis through bacterial spreading or immune function impairment.