History

Fact Explanation
Catarrhal phase:- nonspecific symptoms Symptoms of whooping cough are explained in 3 phases, such as catarrhal, paroxysmal, and convalescent. Bordetella pertussis bacteria produces antigens that can cause local cell damage and may mediate systemic symptoms as well. Symptoms of the catarrhal phase are low-grade fever, malaise due to action of cytokines released to the circulation from the on going inflammation, tearing, red eye and itching of the eye due to mild conjunctival inflammation, rhinorrhea, late-phase nonproductive cough. This phase has insidious onset and persist for 1-2 weeks with gradually worsening of the symptoms.[1,2]
Paroxysmal phase:- characteristic cough Patients develop bouts of coughing which is violent in nature during a single exhalation which is followed by an inspiratory whooping sound. These paroxysms are associated with post-tussive vomiting and cyanosis. Infants can have prolonged coughing. Usually this phase lasts 1-6 weeks. Earlier vaccinated children will present with long-term cough, not cough with violent coughing or whooping attacks as seen in non-vaccinated children making diagnostic difficulties and aid further transmission of the organism within the families, especially to the infants.[1,2,3]
Convalescent phase:- resolution of symptoms Paroxysms resolve slowly, but cough can persist for several months.[1,2]
Poor feeding Found in infants especially neonates.[1]
Difficulty in breathing Since these patients produce a violent cough, they can develop complications like pneumothorax due damage to the pleura following rib fractures, giving rise to difficulty in breathing.[1]
History of close contact with a case of whooping cough The causative organism Bordetella pertussis is an exclusively human pathogen that is transmitted via airborne droplets. Therefore history of close contact with the diagnosis of whooping cough may raise the suspicion of whooping cough in the patient also.[1]
References
  1. GREGORY DS. Pertussis: a disease affecting all ages. Am Fam Physician [online] 2006 Aug 1, 74(3):420-6 [viewed 16 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/16913160
  2. PITTET LF, EMONET S, FRAN├žOIS P, BONETTI EJ, SCHRENZEL J, HUG M, ALTWEGG M, SIEGRIST CA, POSFAY-BARBE KM. Diagnosis of Whooping Cough in Switzerland: Differentiating Bordetella pertussis from Bordetella holmesii by Polymerase Chain Reaction PLoS One [online] , 9(2):e88936 [viewed 16 June 2014] Available from: doi:10.1371/journal.pone.0088936
  3. KORPPI M. Whooping cough--still a challenge. J Pediatr (Rio J) [online] 2013 Nov-Dec, 89(6):520-2 [viewed 19 June 2014] Available from: doi:10.1016/j.jped.2013.09.001

Examination

Fact Explanation
Characteristic cough with a whooping sound Pertussis is primarily a toxin-mediated disease, where the bacteria attach to the cilia of the respiratory epithelial cells, produce toxins that paralyze the cilia, and cause inflammation of the respiratory tract, which interferes with the clearing of pulmonary secretions. Most of the time there are no clinical signs between coughing spasms with inspiratory whooping sound which occur with the narroving of the air way. Inspection of the cough is important in diagnosing the condition.[1]
Apnea Found in infants less than 6 months, especially in neonates as their tiny airways are very much susceptible to occlude completely with little insult.[1]
Bradycardia In neonates heart rate may be slow.[1]
Increased body temperature Uncommon sign, may find in few patients.[1]
Conjunctival hemorrghages Due to violent coughing.[1]
References
  1. GREGORY DS. Pertussis: a disease affecting all ages. Am Fam Physician [online] 2006 Aug 1, 74(3):420-6 [viewed 16 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/16913160

Differential Diagnoses

Fact Explanation
Viral upper respiratory tract infection Important to exclude as most often symptoms of catarrhal stage misdiagnosed as viral upper respiratory tract infection. In viral upper respiratory tract infection, paroxysms won't be there.[1]
Asthma or reactive airway disease Past personal or family history will be positive in asthma. Rhonchi will be heard on auscultation of the lung and reversibility with bronchodialators can be assessed which is not in pertussis.[1,5]
Bronchiolitis Bronchiolitis is an acute inflammation of the bronchioles, most commonly caused by respiratory syncytial virus and found in infants.[1,2]
Acute bronchitis Bronchitis is an inflammation of the mucous membranes of the bronchi.[1,3]
Pneumonia Consider in patients with high grade ferver with chilld and rigors.[1]
Foreign body aspiration Commonly found in toddlers and infants with toddler siblings. Sudden onset coughing, wheezing and stridor raise the suspicion and need immediate intervention.[1,4]
References
  1. WEISS LN. The diagnosis of wheezing in children. Am Fam Physician [online] 2008 Apr 15, 77(8):1109-14 [viewed 16 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/18481558
  2. Diagnosis and Management of Bronchiolitis. PEDIATRICS [online] 2006 October, 118(4):1774-1793 [viewed 18 June 2014] Available from: doi:10.1542/peds.2006-2223
  3. ALBERT RH. Diagnosis and treatment of acute bronchitis. Am Fam Physician [online] 2010 Dec 1, 82(11):1345-50 [viewed 18 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/21121518
  4. DUAN XJ, CHEN YP, QIU J. [Clinical features of tracheobronchial foreign bodies in children]. Zhongguo Dang Dai Er Ke Za Zhi [online] 2014 Apr, 16(4):410-3 [viewed 18 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/24750841
  5. NG CW, HOW CH. PILL series. Recurrent wheeze and cough in young children: is it asthma? Singapore Med J [online] 2014 May, 55(5):236-41 [viewed 18 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/24862744

Investigations - for Diagnosis

Fact Explanation
Culture of a nasopharyngeal swab or an aspirate The causative organism, Bordetella pertussis is very difficult to grow in a culture media. But culture should be done in every patient suspecting whooping cough. Note: when taking the specimen, nasopharyngeal aspirate is better than a swab in terms of recovering bacteria.[1]
Polymerase chain reaction (PCR) assay Should be done to detect the organism and it is more sensitive than culture later in the disease course and is similar in specificity.[1]
Serology - Direct fluorescent antibody test Even though it confirms the diagnosis quickly, need technically qualified trained personnel to perform. Also its sensitivity is lower compared to PCR assay.[1]
Full blood count Patients found to have leukocytosis and lymphocytosis during paroxysmal phase of whooping cough. During convalescent phase these changes usually normalize.[1]
Chest X-ray Important to exclude differntial diagnoses and to detect complications.[1]
References
  1. GREGORY DS. Pertussis: a disease affecting all ages. Am Fam Physician [online] 2006 Aug 1, 74(3):420-6 [viewed 16 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/16913160

Management - General Measures

Fact Explanation
Parent eduation Parents should be educated properly about the disease condition, possible complications, treatment modalities and the importance of drug compliance. Also should be advised not to send the child to school and presence of others outside the home (especially infants and young children) until received 5 days of therapy, or coughing for more than 21 days.[1]
References
  1. GREGORY DS. Pertussis: a disease affecting all ages. Am Fam Physician [online] 2006 Aug 1, 74(3):420-6 [viewed 16 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/16913160

Management - Specific Treatments

Fact Explanation
Hospitallization Most children who developed whooping cough need hospital admission to monitor and detect the complications as soon as possible.[1]
Antimicrobial therapy Whooping cough also known as pertussis is caused by gram negative bacterium called Bordetella pertussis. Therefore these patients need antibiotic therapy to reduce risk of transmission, though it has not been shown reduction in disease duration. Erythromycin is the drug of choice and has to be given for 14 days. Other macrolides such as azithromycin and clarythromycin also can be given and known to have less side effects than erythromycin. [1]
Prevention: Chemoprophylaxis Since whooping cough is highly contagious, chemoprophylaxis should be given to close household contacts to control outbreaks.[1]
Prevention: Vaccination In United States there is increasing deaths due to whooping cough which can be easily prevented by giving pertussis vaccine. Currently 2 types of vaccines are available- whole cell vaccine with lot of adverse events and the acellular vaccine with a good safety profile though it is less effective than the whole cell vaccine. Currently there are changes in the genome of circulating Bordetella pertussis strains most probably due to use of less effective acellular vaccine world wide, only for young children. Vaccinated programs continued only upto 2 years of age of the child due to increasingly reported adverse events with the whole cell vaccine and less severity of disease in older children. Protectiveness of the vaccine is short lived and incomplete. Immunity starts to decrease 4-12 years after vaccination, making school children, adolescents and adults susceptible. Therefore not only young children, adolescents and adults also should receive Tdap vaccination in order to reduce the incidence of pertussis and to prevent the disease transmission from adults to infants.[1,2,3,4]
Monitor and manage complications Associated reported complications of whooping cough are pneumonia, dehydration, weight loss, sleep disturbance, seizures, and, rarely, encephalopathy, refractory pulmonary hypertension or death. Type of complication change according to age of the patient and most victims are infants.[1]
Not recommended drugs Antihistamines, steroids, beta agonists, and immunoglobulins are not recommended for routine use for the whooping cough treatment.[1]
Notification Notification is must and important for prevention of the disease.[1]
Refer to a paediatrician Indications are infants less than 6 months of age, any child with complications.[1]
Transfer to a tertiary care cnetre Any child with complications should be transfered.[1]
References
  1. GREGORY DS. Pertussis: a disease affecting all ages. Am Fam Physician [online] 2006 Aug 1, 74(3):420-6 [viewed 16 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/16913160
  2. CHERRY JD. Pertussis: challenges today and for the future. PLoS Pathog [online] 2013, 9(7):e1003418 [viewed 16 June 2014] Available from: doi:10.1371/journal.ppat.1003418
  3. KORPPI M. Whooping cough--still a challenge. J Pediatr (Rio J) [online] 2013 Nov-Dec, 89(6):520-2 [viewed 19 June 2014] Available from: doi:10.1016/j.jped.2013.09.001
  4. PESCO P, BERGERO P, FABRICIUS G, HOZBOR D. Modelling the effect of changes in vaccine effectiveness and transmission contact rates on pertussis epidemiology. Epidemics [online] 2014 Jun:13-21 [viewed 19 June 2014] Available from: doi:10.1016/j.epidem.2014.04.001