Pulmonology & Rheumatology (Gr. 2 Rotations) Flashcards
Bronchiolitis (& RSV)
Etiology & Clinical manifestations
Which pathogen is mostly accountable for Bronchiolitis?
(and the remainder? [5])
Who is at most risk from severe bronchiolitis?
What are the characteristic findings on examination? (6)
Bronchiolitis is the most common serious respiratory
infection of infancy: 2–3% of all infants are admitted
to hospital with the disease each year during annual
winter epidemics; 90% are aged 1–9 months. RSV is the
pathogen in 80%, the remainder are accounted for by
parainfluenza virus, rhinovirus, adenovirus, influenza
virus, and human metapneumovirus. There is evidence
that co-infection with more than one virus, particularly
RSV and human metapneumovirus may lead to a more
severe illness.
Coryzal symptoms precede a dry cough and increasing
breathlessness. Feeding difficulty associated with
increasing dyspnoea is often the reason for admission
to hospital. Recurrent apnoea is a serious complication,
especially in young infants. Infants born prematurely
who develop bronchopulmonary dysplasia or with
other underlying lung disease, such as cystic fibrosis,
or have congenital heart disease are most at risk from
severe bronchiolitis.
The characteristic findings on examination (Fig. 17.6) are:
- Dry wheezy cough
- Tachypnoea and tachycardia
- Subcostal and intercostal recession
- Hyperinflation of the chest
- Fine end-inspiratory crackles
- High-pitched wheezes – expiratory > inspiratory
Bronchiolitis (& RSV)
Investigations &
Indication for admission to hospital
What investigation is performed in children with suspected bronchiolitis?
What investigation is performed if respiratory failure is suspected?
What signs & symptoms indicate hospital admission?
Pulse oximetry should be performed on all children
with suspected bronchiolitis. No other investigations
are routinely recommended. In particular, chest X-ray
or blood gases are only indicated if respiratory failure
is suspected.
Hospital admission is indicated if any of the following
are present:
- Apnoea (observed or reported)
- Persistent oxygen saturation of < 90% when breathing air
- Inadequate oral fluid intake (50–75% of usual volume)
- Severe respiratory distress – grunting, marked chest recession, or a respiratory rate over 70 breaths/minute
Bronchiolotis (& RSV)
Management
How to manage Bronchiolitis? (4)
This is supportive. Humidified oxygen is either delivered
via nasal cannulae or using a head box; the concentration
required is determined by pulse oximetry. The
infant is monitored for apnoea.
No evidence for reducing
severity or illness duration has been shown from
use of mist, nebulized hypertonic saline, antibiotics,
corticosteroids or nebulized bronchodilators, such as
salbutamol or ipratropium.
Fluids may need to be given
by nasogastric tube or intravenously.
Assisted ventilation
in the form of non-invasive respiratory support
with CPAP (continuous positive airway pressure) or else
mechanical ventilation is required in a small percentage
of infants admitted to hospital [see Case History
6.1 in Ch. 6 (Paediatric emergencies)].
RSV is highly
infectious, and infection control measures, particularly
good hand hygiene, cohort nursing, and gowns and
gloves, have been shown to prevent cross-infection to
other infants in hospital.
Most infants recover from the acute infection within
2 weeks. However, as many as half will have recurrent
episodes of cough and wheeze (see the following
section). Rarely, usually following adenovirus infection,
the illness may result in permanent damage to the
airways (bronchiolitis obliterans).
Croup
Etiology and Epidemiology
Croup is the most common infection of…
The most common causes of croup are…
What symptom is characteristic of croup?
At which ages is croup most common?
Croup, or laryngotracheobronchitis, is the most common
infection of the middle respiratory tract.
The most common
causes of croup are parainfluenza viruses (types 1, 2, 3, and 4)
and respiratory syncytial virus (RSV).
Laryngotracheal airway
inflammation disproportionately affects children because a small
decrease in diameter secondary to mucosal edema and inflammation
exponentially increases airway resistance and the work
of breathing. During inspiration, the walls of the subglottic
space are drawn together, aggravating the obstruction and
producing the stridor characteristic of croup.
Croup is most
common in children 6 months to 3 years of age, with a peak
in fall and early winter. It typically follows a common cold.
Symptomatic reinfection is common, yet reinfections are usually
mild. In adolescents, it manifests as laryngitis.
Croup
Clinical manifestations
The manifestations of croup are… (6)
Signs of upper airway obstruction… (3)
Sign of lower airway involvement (1)
The manifestations of croup are a harsh cough described as
barking or brassy, hoarseness, inspiratory stridor, low-grade
fever, and respiratory distress that may develop slowly or
quickly.
Stridor is a harsh, high-pitched respiratory sound
produced by turbulent airflow. It is usually inspiratory, but
it may be biphasic and is a sign of upper airway obstruction.
Signs of upper airway obstruction, such as labored breathing,
cyanosis, and marked suprasternal, intercostal, and subcostal
retractions, may be evident on examination (see Chapter 135).
- *Wheezing may be present if there is associated lower airway
involvement. **
Croup
Laboratory and imaging studies
What radiographic sign of croup leads to diagnosis?
What other tests can be performed?
Anteroposterior radiographs of the neck often show the
diagnostic subglottic narrowing of croup known as the steeple
sign (Fig. 107.1).
Routine laboratory studies are not useful in
establishing the diagnosis. Leukocytosis is uncommon and
suggests epiglottitis or bacterial tracheitis.
Many rapid tests
(using polymerase chain reaction [PCR]) are available for
parainfluenza viruses, RSV, and other less common viral causes
of croup, such as influenza and adenoviruses.
Croup
Treatment
Which two corticosteroids may be given and in what doses? (2)
Oral or intramuscular dexamethasone for children with croup
reduces symptoms and the need for hospitalization, and shortens
hospital stays.
Dexamethasone (0.6-1 mg/kg) may be given
once intramuscularly or orally.
Alternatively, prednisolone
(2 mg/kg/day) may be given orally in two to three divided
doses.
For significant airway compromise, administration of
aerosolized racemic (D- and L-)epinephrine reduces subglottic
edema by adrenergic vasoconstriction, temporarily producing
marked clinical improvement. The peak effect is within 10-30
minutes and fades within 60-90 minutes. A rebound effect may
occur, with worsening of symptoms as the effect of the drug
dissipates. Aerosol treatment may need to be repeated every
20 minutes (for no more than 1-2 hours) in severe cases.
Children should be kept as calm as possible to minimize
forceful inspiration. One useful calming method is for a child
with croup to sit on the parent’s lap. Sedatives should be
used cautiously and in the intensive care unit only. Cool mist
administered by face mask may help prevent drying of the
secretions around the larynx.
Hospitalization is often required for children with cyanosis,
or stridor at rest. Children receiving aerosol treatment should
be hospitalized or observed for at least 2-3 hours because of the
risk of rebound airway obstruction. Decreased symptoms may
indicate improvement or fatigue, and impending respiratory
failure.
Croup
Complications and Prognosis
What is the most common complication of croup?
What other complications of croup are there? (3)
The most common complication of croup is viral pneumonia,
which occurs in 1-2% of children.
Parainfluenza virus pneumonia
and secondary bacterial pneumonia are more common
in immunocompromised patients. Bacterial tracheitis may also
be a complication of croup.
The prognosis for croup is excellent. Illness usually lasts
approximately 5 days. As children grow, they become less
susceptible to the airway effects of viral infections of the middle
respiratory tract.
Asthma
(including exacerbations)
Clinical manifestations
Symptoms (5)
Common exacerbating factors (6)
Manifestations during acute episodes (5)
Children with asthma have symptoms of coughing, wheezing,
shortness of breath, exercise intolerance, or chest tightness.
The history should elicit the frequency, severity, and precipitating
factors as well as a family history of asthma and allergy.
Common exacerbating factors include viral infections, exposure to
allergens and irritants (e.g., smoke, air pollution, strong odors,
fumes), exercise, emotions, and change in weather/humidity.
Nocturnal symptoms are common. Rhinosinusitis, gastroesophageal
reflux, and aspirin can aggravate asthma. Treatment of
these conditions may lessen the frequency and severity of
asthma.
During acute episodes, tachypnea, tachycardia, cough, wheezing,
and a prolonged expiratory phase may be present. Physical
findings may be subtle. Wheezing may not be prominent if
there is poor aeration from airway obstruction. As the attack
progresses, cyanosis, diminished air movement, retractions,
agitation, inability to speak, tripod sitting position, diaphoresis,
and pulsus paradoxus (decrease in blood pressure of >15 mm
Hg with inspiration) may be observed. Physical examination
may show evidence of other atopic diseases such as eczema
or allergic rhinitis.
Asthma
Laboratory and imaging studies
Which objective measurement aids in the diagnosis and direct the treatment of asthma?
What other test should be incluced in the evaluation of children with persistent asthma?
What imaging should be utilized and when?
How may asthma and airway inflammation be monitored?
While no single test or study can confirm the diagnosis of
asthma, many elements contribute to establishing the
diagnosis.
Objective measurements of pulmonary function (spirometry)
aid in the diagnosis and direct the treatment of asthma.
Spirometry is used to monitor response to treatment, assess
degree of reversibility to therapeutic intervention, and measure
the severity of an asthma exacerbation. Children older than 5
years of age can usually perform spirometry maneuvers. Variability
in predicted peak flow reference values make spirometry
preferred over peak flow measures in the diagnosis of asthma.
For younger children who cannot perform spirometry maneuvers
or peak flow, a therapeutic trial of controller medications aids
in the diagnosis of asthma.
Allergy skin testing should be included in the evaluation
of all children with persistent asthma but not during an exacerbation
of symptoms. Positive skin test results, identifying
sensitization to aeroallergens (e.g., pollens, mold, dust mite,
pet dander), correlate strongly with bronchial allergen provocative
challenges. In vitro serum tests, such as enzyme-linked
immunosorbent assay (ELISA), are generally less sensitive in
defining clinically pertinent allergens, are more expensive, and
require several days for results, compared to several minutes
for skin testing (see Table 77.4).
An x-ray should be performed with the first episode of
asthma or with recurrent episodes of undiagnosed cough
or wheeze to exclude anatomic abnormalities. Repeat chest
x-rays are not needed with new episodes unless there is fever
(suggesting pneumonia) or localized findings on physical
examination.
Two novel forms of monitoring asthma and airway inflammation
directly include exhaled nitric oxide analysis and
quantitative analysis of expectorated sputum for eosinophilia.
Asthma
Treatment
What should be available for all children with asthma?
What is the difference between intermittent and persistent asthma? (Rules of Two)
What is the preferred initial long-term control therapy?
Daily longterm control therapy is recommended for infants and young
children 0-4 years of age who had… (3)
Treatment for children over 5 years of age with moderate persistent asthma
Treatment for children with severe persistent asthma
Medication type, dose, and dosing intervals
are determined by the level of asthma severity or asthma control.
Therapy is then increased (stepped up) as necessary and
decreased (stepped down) when possible. A short-acting
bronchodilator should be available for all children with asthma.
A child with intermittent asthma has asthma symptoms less
than two times per week. To determine whether a child is
having more persistent asthma, using the Rules of Two is helpful:
daytime symptoms occurring two or more times per week or
nocturnal awakenings two or more times per month implies
a need for daily antiinflammatory medication.
Inhaled corticosteroids are the preferred initial long-term
control therapy for children of all ages (Fig. 78.3).
Daily longterm
control therapy is recommended for infants and young
children 0-4 years of age who had four or more episodes of
wheezing in the previous year that lasted more than 1 day,
affected sleep, and who have a positive asthma predictive index.
For children over 5 years of age with moderate persistent asthma,
combining long-acting bronchodilators with low-to-medium
doses of inhaled corticosteroids improves lung function and
reduces rescue medication use.
For children with severe persistent
asthma, a high-dose inhaled corticosteroid combined
with a long-acting bronchodilator is the preferred therapy.
The guidelines also recommend that treatment be reevaluated
within 4-6 weeks of initiating therapy. Once asthma is under
control, control should be assessed on an ongoing basis every
1-6 months. The asthma should be well controlled for at least
3 months before stepping down therapy.
Asthma
Complications (Exacerbations)
What is status asthmaticus?
What characterizes deterioration in asthma control? (5)
First-line management of asthma exacerbations includes…
Early administration of […] or […] is important in treating the underlying inflammation
What is given and in what dose, when treatment with β2-agonists, ipratropium,
and systemic corticosteroids fail?
Most asthma exacerbations can be successfully managed at
home. Status asthmaticus is an acute exacerbation of asthma
that does not respond adequately to therapeutic measures and
may require hospitalization. Exacerbations may progress over
several days or occur suddenly and can range in severity from
mild to life threatening. Significant respiratory distress, dyspnea,
wheezing, cough, and a decrease in spirometry or peak expiratory
flow rate (PEFR) characterize deterioration in asthma
control. During a severe episode, pulse oximetry is helpful in
monitoring oxygenation. In status asthmaticus, arterial blood
gases may be necessary for measurement of ventilation. As
airway obstruction worsens and chest compliance decreases,
carbon dioxide retention can occur. In the face of tachypnea,
a normal PCO2 (35-45 mm Hg) indicates impending respiratory
arrest.
First-line management of asthma exacerbations includes
supplemental oxygen if needed and repetitive or continuous
administration of short-acting bronchodilators.
Early administration
of oral or intravenous corticosteroids (Fig. 78.4) is important
in treating the underlying inflammation.
Administration of
anticholinergic agents (ipratropium) with bronchodilators
decreases rates of hospitalization and duration of time in the
emergency department. Intravenous magnesium sulfate is
administered in the emergency department if there is clinical
deterioration despite treatment with β2-agonists, ipratropium,
and systemic corticosteroids. The typical dose of magnesium
sulfate is 25-75 mg/kg (maximum 2.0 g) intravenously
administered over 20 minutes. Intramuscular epinephrine or
subcutaneous terbutaline are rarely used except when severe
asthma is associated with anaphylaxis or unresponsive to
continuous administration of short-acting bronchodilators.
Cystic Fibrosis
Etiology and Epidemiology
Where is the gene for CF located?
What is CFTR?
What is the most common mutation?
The altered chloride ion conductance in
the sweat gland results in…
What is the diagnostic criteria for CF?
Cystic fibrosis (CF) is a life-shortening autosomal recessive
disorder that affects over 70,000 individuals worldwide. Although
found predominantly in people of European descent, CF is
reported among all races and ethnicities.
The gene for CF, located
on the long arm of chromosome 7, encodes for the cystic fibrosis
transmembrane conductance regulator (CFTR), a chloride
channel located on the apical surface of epithelial cells.
CFTR is important for the proper movement of salt and water across
cell membranes and maintaining the appropriate composition
of various secretions, especially in the airways, liver, and pancreas.
The most common mutation is a deletion of three
base pairs resulting in the absence of phenylalanine at the 508
position (Phe508del, F508del). Nearly 2,000 mutations of the
CFTR gene have been identified to date.
The secretory and absorptive characteristics of epithelial
cells are affected by abnormal CFTR, resulting in the clinical
manifestations of CF. The altered chloride ion conductance in
the sweat gland results in excessively high sweat sodium and
chloride levels.This is the basis for the sweat chloride test,
which is still the standard diagnostic test for this disorder.
It is positive (elevated sweat chloride ≥60 mEq/L) in 99% of
patients with CF.
Abnormal airway secretions make the airway
more prone to colonization with bacteria. Defects in CFTR
may also reduce the function of airway defenses and promote
bacterial adhesion to the airway epithelium. This ultimately
leads to chronic airway infections and eventually to bronchial
damage (bronchiectasis).
Cystic Fibrosis Clinical Manifestations (1/5)
What is common in patients with CF, even in those without significant lung disease?
What is also common?
CF is a chronic progressive disease that can present with protein
and fat malabsorption (failure to thrive, hypoalbuminemia,
steatorrhea), liver disease (cholestatic jaundice), or chronic
respiratory infection.
Older children have traditionally presented with pulmonary
manifestations such as chronic cough, poorly controlled asthma, and
chronic respiratory infections, but recurrent pancreatitis, nasal
polyps, and chronic sinusitis can also be presenting manifestations.
The respiratory epithelium of patients with CF exhibits
marked impermeability to chloride and an excessive reabsorption
of sodium. This leads to thicker airway secretions, resulting in
airway obstruction and impaired mucociliary transport. This,
in turn, leads to endobronchial colonization with bacteria,
especially Staphylococcus aureus and Pseudomonas aeruginosa.
Chronic bronchial infection results in persistent or recurrent
cough that is often productive of sputum, especially in older
children. Chronic airway infection leads to airway obstruction
and bronchiectasis and, eventually, to pulmonary insufficiency
and premature death. The median age of survival is currently
>40 years. Digital clubbing is common in patients with CF,
even in those without significant lung disease.
Chronic sinusitis
and nasal polyposis are common.
Cystic Fibrosis Clinical Manifestations (2/5)
Pulmonary infections with […] and some strains of
[…] are difficult to treat and may be associated with […]
What is Allergic bronchopulmonary
aspergillosis (ABPA)?
Treatment for ABPA?
Pulmonary infections with P. aeruginosa and some strains of
Burkholderia cepacia are difficult to treat and may be associated
with accelerated clinical deterioration.
Allergic bronchopulmonary
aspergillosis (ABPA) is a hypersensitivity reaction to
Aspergillus in the CF airways. It causes airway inflammation/
obstruction and aggravates CF lung disease.
The treatment for
ABPA is systemic corticosteroids (prednisone) and antifungal
agents (itraconazole).
Minor hemoptysis is usually due to airway
infection, but major hemoptysis is often caused by bleeding
from bronchial artery collateral vessels in damaged/chronically
infected portions of the lung. Pneumothoraces can occur in
patients with advanced lung disease.
Pneumonia
Clinical features
What are the most common presenting symptoms? (3)
Other symptoms include… (3)
What may be a feature of pleural irritation, and what does it suggest?
What may physical examination reveal? (5)
What may confirm the diagnosis?
But it cannot do what?
Fever, cough and rapid breathing are the most common
presenting symptoms. These are usually preceded by a
URTI.
Other symptoms include lethargy, poor feeding,
and an ‘unwell’ child. Some children do not have a
cough at presentation.
Localized chest, abdominal, or
neck pain is a feature of pleural irritation and suggests
bacterial infection.
Examination reveals tachypnoea, nasal flaring and
chest indrawing. In contrast to asthma, the most sensitive
clinical sign of pneumonia in children is increased
respiratory rate, and pneumonia can sometimes be
missed if the respiratory rate is not measured in a
febrile child (so-called silent pneumonia). There may be
end-inspiratory coarse crackles over the affected area
but the classic signs of consolidation with dullness on
percussion, decreased breath sounds and bronchial
breathing over the affected area are often absent in
young children. Oxygen saturation may be decreased.
A chest X-ray may confirm the diagnosis (Fig. 17.18)
but cannot reliably differentiate between bacterial and
viral pneumonia. In younger children, a nasopharyngeal
aspirate may identify viral causes, but blood tests,
including full blood count and acute-phase reactants
are generally unhelpful in differentiating between
a viral and bacterial cause. In a small proportion of
children the pneumonia is associated with a pleural
effusion, where there may be blunting of the costophrenic
angle on the chest X-ray (Fig. 17.19). Some
of these effusions develop into empyema and fibrin
strands may form, leading to septations.
Pneumonia
Management
Indication for admission include… (4)
General supportive care should include… (2)
Newborns require… [drug]
Most older infants can be managed with… [drug]
What can be reserved for older infants with complicated or unresponsive pneumonia? [drug]
For children over 5 years of age… [drug]
Persistent fever despite 48 hours of antibiotics may suggest what?
And what does it require? (management)
Evidence-based guidelines for the management
of pneumonia in childhood have been published
(British Thoracic Society). Most affected children can
be managed at home but indications for admission
include oxygen saturation <92%, recurrent apnoea,
grunting and/or an inability to maintain adequate
fluid/feed intake.
General supportive care should
include oxygen for hypoxia and analgesia if there is
pain. Intravenous fluids should be given if necessary to
correct dehydration and maintain adequate hydration
and sodium balance. Physiotherapy has no proven role.
The choice of antibiotic is determined by the child’s
age and the severity of illness.
Newborns require broadspectrum
intravenous antibiotics.
Most older infants
can be managed with oral amoxicillin, with broader spectrum
antibiotics such as co-amoxiclav reserved for
complicated or unresponsive pneumonia.
For children
over 5 years of age, either amoxicillin or an oral macrolide
such as erythromycin is the treatment of choice.
There is no advantage in giving intravenous rather than
oral treatment in mild/moderate pneumonia.
Small parapneumonic effusions occur in up to one third
of children with pneumonia and may resolve with
appropriate antibiotics, but persistent fever despite
48 hours of antibiotics suggests a pleural collection
which requires drainage (Fig. 17.19). This should be
done with ultrasound guidance. The percutaneous
placement of a small-bore chest drain and regular
instillation of a fibrinolytic agent to break down the
fibrin strands are usually effective, but more aggressive
intervention such as video-assisted thoracoscopic
surgery or even thoracotomy and decortication is
sometimes necessary in refractory cases.
Juvenile Idiopathic Arthritis (JIA)
Clinical Presentation
The child may develop… (5)
What is present on physical examination? (3)
All children with chronic arthritis are at risk for… (2)
Which subgroup of JIA is at highest risk for [second answer to question 2]?
JIA can be divided into several subtypes, depending on the
number of joints involved (<5 versus 5 or more), the presence
of sacroiliac involvement, and the presence of systemic features,
each with particular disease characteristics (Table 89.1).
Although the onset of the arthritis is slow, the actual joint
swelling is often noticed acutely by the child or parent, such
as after an accident or fall, and can be confused with trauma
(even though traumatic effusions are rare in children). The
child may develop pain and stiffness in the joint that limit use,
but refusing to bear weight on the joint is rare. Morning stiffness
and gelling also can occur in the joint and, if present, can be
followed in response to therapy.
On physical examination, signs of inflammation are present,
including joint tenderness, erythema, and effusion (Fig. 89.1).
Joint range of motion may be limited because of pain, swelling,
or contractures from lack of use. In children, because of the
presence of an active growth plate, it may be possible to find
bony abnormalities of the surrounding bone, causing bony
proliferation and localized growth disturbance. In a lower
extremity joint, a leg length discrepancy may be appreciable
if the arthritis is asymmetric.
All children with chronic arthritis are at risk for chronic
iridocyclitis or uveitis. There is an association between human
leukocyte antigens (HLAs; HLA-DR5, HLA-DR6, and HLA-DR8)
and uveitis. The presence of a positive antinuclear antibody
identifies children with arthritis who are at higher risk for
chronic uveitis. Although all children with JIA are at increased
risk, the subgroup of children, particularly young girls, with
oligoarticular (<5 affected joints) JIA and a positive antinuclear
antibody are at highest risk, with an incidence of uveitis of
80%. The uveitis associated with JIA can be asymptomatic until
the point of visual loss, making it the primary treatable cause
of blindness in children. It is crucial for children with JIA to
undergo regular ophthalmological screening with a slit-lamp
examination to identify anterior chamber inflammation and
to initiate prompt treatment of any active disease.
JIA (Not really)
Spondyloarthropathies
The spondyloarthropathies describe a
group of arthritides that include… (2)
Examples of spondyloarthropathies (3)
Other important features of this group include the frequent
presence of […] and the need for earlier treatment with […]
The spondyloarthropathies describe a group of arthritides that
include inflammation of the axial skeleton and sacroiliac joints
and enthesitis, or inflammation of tendinous insertions.
These include juvenile ankylosing spondylitis, psoriatic arthritis,
and the arthritis of inflammatory bowel disease.
This group of
diseases can also present with peripheral arthritis and can be
initially classified in other subgroups. It is only later, when the
patient develops evidence of sacroiliac arthritis, psoriasis, or
gastrointestinal disease, that the diagnosis becomes clear (Table
89.2).
Other important features of this group include the frequent
presence of HLA-B27 and the need for earlier treatment with
tumor necrosis factor (TNF) blockers.
HSP
Clinical Manifestations
HSP is characterized by…
The hallmark of HSP is…
The rash is classically
found in… (3)
Arthritis in HSP is most common in…
Gastrointestinal involvement occurs in […] and most typically presents as […], thought to be due to […] leading to […].
How many children develop renal involvement?
HSP is characterized by rash, arthritis, and less frequently
gastrointestinal or renal vasculitis.
The hallmark of HSP is
palpable purpura, caused by small vessel inflammation in the
skin, leading to extravasation of blood into the surrounding
tissues, frequently with IgA deposition.
The rash is classically
found in dependent areas: below the waist, on the buttocks,
and lower extremities (Fig. 87.1). The rash can begin as small
macules or urticarial lesions but rapidly progresses to purpura
with areas of ecchymosis. The rash also can be accompanied
by edema, particularly of the calves and dorsum of the feet,
scalp, and scrotum or labia. HSP occasionally is associated with
encephalopathy, pancreatitis, and orchitis.
Arthritis occurs in 80% of patients with HSP and is most
common in the lower extremities, particularly the ankles and
knees. The arthritis is acute and very painful, with refusal to
bear weight. Joint swelling can be confused with peripheral
edema seen with the rash of HSP.
Gastrointestinal involvement occurs in about one half of
affected children and most typically presents as mild to moderate
crampy abdominal pain, thought to be due to small vessel
involvement of the gastrointestinal tract leading to ischemia. Less
commonly, significant abdominal distention, bloody diarrhea,
intussusception, or abdominal perforation occurs and requires
emergent intervention. Gastrointestinal involvement is typically
seen during the acute phase of the illness. It may precede the
onset of rash.
One third of children with HSP develop renal involvement,
which can be acute or chronic.Although renal involvement
is mild in most cases, acute glomerulonephritis manifested
by hematuria, hypertension, or acute renal failure can occur.
Most cases of glomerulonephritis occur within the first few
months of presentation, but rarely patients develop late renal
disease, which ultimately can lead to chronic renal disease,
including renal failure.
HSP
Diagnosis
The diagnosis of HSP is based on the presence of two of four
criteria (Table 87.1), which provides 87.1% sensitivity and 87.7%
specificity for the disease.
The differential diagnosis includes
other systemic vasculitides (Table 87.2) and diseases associated
with thrombocytopenic purpura, such as idiopathic thrombocytopenic
purpura and leukemia.
