Pediatric Annals

COMMON PEDIATRIC SURGICAL PROBLEMS 

Evaluation of the Child With Suspected Appendicitis

Randall S Burd, MD, PhD; Thomas V Whalen, MD

Abstract

Pediatric surgeons are frequently consulted to evaluate children for the potential diagnosis of acute appendicitis. Appendicitis is a common entity with a lifetime risk of approximately 9% in males and 7% in females.1 It is diagnosed in between 1% and 8% of children presenting to the emergency department for evaluation of abdominal pain.2'3 Although appendicitis can occur in all age groups, it most frequently presents in the second decade of life and is not infrequent in the first decade. Appendectomy is the most common emergency surgical procedure performed in chñdren.1 This article presents an approach for evaluating children with possible appendicitis from the perspective of a pediatric surgeon.

SYMPTOMS AND SIGNS

A "typical" sequence of symptoms (eg, periumbilical pain, anorexia, nausea, right lower quadrant abdominal pain, and vomiting followed by fever) is often not observed in children with appendicitis.4 However, mis order of symptoms should be considered when evaluating a child with potential appendicitis. Abdominal pain mat is vague and centered in the periumbilical region is often the first symptom of appendicitis. This pain eventually localizes to the right lower quadrant over several hours to a few days. Atypical presentations of the initial symptom of pain may be observed in patients with a retrocecal appendix, an appendix directed into the pelvis, or an appendix in an abnormal intraabdominal position such as might occur with nonrotation.5 Prominent flank or back pain and less anterior abdominal pain may be observed in patients with an extraperitoneal and retrocecal appendix. Urinary symptoms, including testicular or penile pain or pain with urination, may be observed when an inflamed appendix irritates the ureter or bladder. These atypical presentations may contribute to a delay in diagnosis and a higher perforation rate.5

Other gastromtestinal symptoms may follow the initial presentation of pain, including anorexia, nausea, and vomiting. Anorexia typically presents as decreased interest in, or avoidance of, food. Preschool children are less reliable historians than are older children or adults, and may express a desire for their favorite food even when their recent history suggests food avoidance. The symptom of nausea should be elicited in children, although this is frequently difficult to do in preschool children. Vomiting may accompany nausea, but frequent vomiting suggests an alternative diagnosis, such as gastroenteritis. The patienf s bowel movement pattern predating the onset or following the development of aMorninal pain is typically normal. Diarrhea may be observed, but is usually not a prominent symptom. However, abdominal pain that is associated with diarrhea can be an initial presentation for either appendicitis or gastroenteritis. A history should be elicited regarding previous episodes of abdominal symptoms requiring medical evaluation. In addition to the remote possibility of recurrent appendicitis, inflammatory bowel disease should be considered, particularly in older children who have had frequent episodes of abdominal pain. Although appendicitis has been shown to have a familial tendency, the high prevalence of this disease may limit the usefulness of this observation.6,7

The patient with appendicitis appears ill. Children who are active in bed and comfortable sitting up and stretching are not likely to have appendicitis. Similarly, a child first observed to be active and screaming in pain is not likely to have appendicitis. The child with appendicitis may lie on one side in a curled up position, tends to move slowly, and has an overall lack of energy. Refusal to walk, walking in a hunched over position, or walking with a limp may be observed and is most likely due to an inflamed appendix near the hip extensor muscles. Observing the child standing and walking without assistance or jumping can be diagnostically useful. A low-grade fever is…

Pediatric surgeons are frequently consulted to evaluate children for the potential diagnosis of acute appendicitis. Appendicitis is a common entity with a lifetime risk of approximately 9% in males and 7% in females.1 It is diagnosed in between 1% and 8% of children presenting to the emergency department for evaluation of abdominal pain.2'3 Although appendicitis can occur in all age groups, it most frequently presents in the second decade of life and is not infrequent in the first decade. Appendectomy is the most common emergency surgical procedure performed in chñdren.1 This article presents an approach for evaluating children with possible appendicitis from the perspective of a pediatric surgeon.

SYMPTOMS AND SIGNS

A "typical" sequence of symptoms (eg, periumbilical pain, anorexia, nausea, right lower quadrant abdominal pain, and vomiting followed by fever) is often not observed in children with appendicitis.4 However, mis order of symptoms should be considered when evaluating a child with potential appendicitis. Abdominal pain mat is vague and centered in the periumbilical region is often the first symptom of appendicitis. This pain eventually localizes to the right lower quadrant over several hours to a few days. Atypical presentations of the initial symptom of pain may be observed in patients with a retrocecal appendix, an appendix directed into the pelvis, or an appendix in an abnormal intraabdominal position such as might occur with nonrotation.5 Prominent flank or back pain and less anterior abdominal pain may be observed in patients with an extraperitoneal and retrocecal appendix. Urinary symptoms, including testicular or penile pain or pain with urination, may be observed when an inflamed appendix irritates the ureter or bladder. These atypical presentations may contribute to a delay in diagnosis and a higher perforation rate.5

Other gastromtestinal symptoms may follow the initial presentation of pain, including anorexia, nausea, and vomiting. Anorexia typically presents as decreased interest in, or avoidance of, food. Preschool children are less reliable historians than are older children or adults, and may express a desire for their favorite food even when their recent history suggests food avoidance. The symptom of nausea should be elicited in children, although this is frequently difficult to do in preschool children. Vomiting may accompany nausea, but frequent vomiting suggests an alternative diagnosis, such as gastroenteritis. The patienf s bowel movement pattern predating the onset or following the development of aMorninal pain is typically normal. Diarrhea may be observed, but is usually not a prominent symptom. However, abdominal pain that is associated with diarrhea can be an initial presentation for either appendicitis or gastroenteritis. A history should be elicited regarding previous episodes of abdominal symptoms requiring medical evaluation. In addition to the remote possibility of recurrent appendicitis, inflammatory bowel disease should be considered, particularly in older children who have had frequent episodes of abdominal pain. Although appendicitis has been shown to have a familial tendency, the high prevalence of this disease may limit the usefulness of this observation.6,7

The patient with appendicitis appears ill. Children who are active in bed and comfortable sitting up and stretching are not likely to have appendicitis. Similarly, a child first observed to be active and screaming in pain is not likely to have appendicitis. The child with appendicitis may lie on one side in a curled up position, tends to move slowly, and has an overall lack of energy. Refusal to walk, walking in a hunched over position, or walking with a limp may be observed and is most likely due to an inflamed appendix near the hip extensor muscles. Observing the child standing and walking without assistance or jumping can be diagnostically useful. A low-grade fever is typical. High fever is not usually observed with uncomplicated appendicitis, but may occur after perforation. The early presentation of high fever suggests a diagnosis other than appendicitis.

When the child suspected of having appendicitis has sufficient symptoms to prompt medical evaluation, the physical examination usually reveals right lower quadrant tenderness with evidence of peritoneal irritation. Three findings should be sought on physical examination in the patient with possible appendicitis: (1) Rovsing's sign or referred pain to the right lower quadrant with palpation of the right side of the abdomen; (2) the psoas sign or abdominal pain with right hip flexion against resistance; and (3) the obturator sign or pain on passive internal rotation of the flexed right thigh. These findings are nonspecific and can usually be elicited in patients with obvious right lower quadrant tenderness by anterior abdominal examination. Peritonitis can be determined using the caf s eye symptom (pain on going over a bump in the road), the cough sign (abdominal tenderness with coughing), right lower quadrant tenderness, percussion tenderness, rebound tenderness, or guarding. A study in adults has shown mat rebound tenderness is the most sensitive and specific of these tests for peritonitis.8

The genitourinary examination in boys should focus on right testicular pathology, including epididymitis or torsion, because this may also present with right lower quadrant pain. Children, particularly adolescent boys, may not report their genital symptoms because of embarrassment or a lack of understanding. The genitourinary examination should also be performed in girls. In younger children, the perineum should be inspected for obvious pathology. Older girls should undergo a rectal-abdominal examination or pelvic examination as indicated.

It is controversial whether a rectal examination is mandatory for establishing a diagnosis of appendicitis in children.9 Although rectal tenderness may be elicited in children with an appendix directed into the pelvis, this examination does not add information that is not available by anterior abdominalexamination. However, failure to have performed a rectal examination is commonly observed in patients with appendicitis who had been seen in the emergency department and discharged with another diagnosis. Rectal examinations are also less commonly performed in cases of missed appendicitis that lead to malpractice claims.10 These observations may relate to how completely the initial examination was performed in general rather than indicate that a rectal examination is always needed. Although it is a nonspecific and insensitive test for appendicitis, the rectal examination has a role for children for whom this diagnosis is not clear by other measures.

Patients with a perforated appendix will have more significant symptoms and signs. Anorexia, nausea, vomiting, and a high fever are frequently observed and the child usually appears ill. Abdominal tenderness is usually more severe, may be generalized to the entire abdomen, and may be associated with peritonitis. A rectal examination may demonstrate fullness consistent with a forming pelvic abscess.

LABORATORY AND IMAGING STUDIES

No single test will diagnose appendicitis unequivocally. Overall, a white blood cell count with differential is the most useful.11 Although the white blood cell count is higher and a left shift is more frequently observed in children with appendicitis, these findings do not distinguish simple appendicitis from perforated appendicitis.11 An elevated white blood cell count may be observed in children with gastroenteritis, pelvic inflammatory disease, and infectious diseases associated with abdominal pain other than appendicitis. A urinalysis should be obtained in patients who have prominent urinary symptoms to rule out a urinary tract infection. Microscopic pyuria or hematuria may be found in patients who have an inflamed appendix near the bladder. Those with gross hematuria or pyuria should be considered to have an alternative diagnosis. Urinalysis has not been found useful in establishing the diagnosis of appendicitis and is most effective when urinary tract infections or renal stones are unlikely.11

Figure 1. Age and gender groups with "typical" and "atypical" presentations of acute appendicitis.

Figure 1. Age and gender groups with "typical" and "atypical" presentations of acute appendicitis.

An abdominal radiograph is not useful for estabHshing the diagnosis of appendicitis in children, but may have a role in the treatment of those who present with abdominal distention or diffuse peritonitis.11,12 The presence of a fecalith on a plain abdominal film has been used in the past to corroborate the diagnosis of appendicitis. The utility of this finding for deterriiining the need for appendectomy has recently been questioned.13 The plain film may be of value when patients present with significant abdominal pain but only mild tenderness and no other evidence of inflammation. In constipated children, an abdominal radiograph showing stool from the rectum through to the cecum may be useful in estabHshing the correct diagnosis.

Ultrasound and abdominal computed tomography (CT) scans have a limited role in the treatment of most cnildren with potential appendicitis and should not be routine. When done for all children with suspected appendicitis, these imaging studies may actually lead to a delay in surgical treatment and increased cost. Ultrasonography may visualize a distended appendix or a noncompressible appendix, supporting the diagnosis of appendicitis. This is also a useful study for evaluating pelvic pathology in adolescent girls.14 An abdominal CT scan with oral contrast may also be useful in children with atypical symptoms and signs. Additional imaging studies are also useful for patients in whom perforation is suspected, and when initial nonoperative management is being considered. In these cases, a right lower quadrant abscess may be found that can be drained percutaneously. Interval appendectomy can then proceed more safely several weeks later, after periappendiceal iriflammation has resolved. Because of the time required to perform them and the expense of both ultrasound and abdominal CT scans, these studies should be reserved for children in whom the diagnosis remains in doubt despite evaluation by an experienced surgeon, adolescent girls with suspected pelvic pathology, and children with a suspected intra-abdominal abscess who are being considered for interval appendectomy.15,17

SPECIAL CATEGORIES OF CHILDREN WITH APPENDICITIS

Although appendicitis can be diagnosed accurately in most children based on history and physical examination, the diagnosis is more difficult in younger children and adolescent girls (Fig. 1). Patients in these groups need to be considered as special categories because of their unique presentation and because initial misdiagnosis frequently occurs.

Children Younger Than 7 Years

The diagnosis of acute appendicitis can be difficult in patients who are younger than 7 years because a "typical" presentation is unusual.18-22 These younger patients often have a clinical presentation that suggests an upper respiratory tract infection, a urinary tract infection, or gastroenteritis. Although most will have abdoniinal pain and tenderness, other findings such as an upper respiratory tract infection, diarrhea, and vomiting are frequently observed and lead to confusion with other diagnoses. A physician will have first seen the child, given a diagnosis other than appendicitis, and discharged the child from the clinic or the emergency department. This course has been observed in 26% to 44% of such young children with appendicitis.19-21 Because establishing this diagnosis in this age group is difficult, a delay from the time of first symptoms until surgery is frequent, and most children younger than 7 years have perforation.18-23 When the diagnosis of appendicitis is not clear in this age group, additional imaging studies (particularly a CT scan of the abdomen) should be considered. A timely diagnosis in the youngest children with a perforated appendix is critical because they are least able to handle diffuse peritonitis.

Adolescent Girls

The differential diagnosis of abdominal pain can be difficult in adolescent girls. Approximately one-third with appendicitis are initially misdiagnosed. Those who are misdiagnosed are more likely to have abnormal pelvic findings on physical examination, including diffuse or bilateral lower abdominal pain and tenderness, cervical motion tenderness, or right adnexal tenderness. Right lower quadrant pain and tenderness and focal or diffuse peritonitis are less common.24 Tubo-ovarian pathology must be considered in the differential diagnosis of right lower quadrant abdominal pain. These diagnoses include mittelschmerz, ovarian torsion, pelvic inflammatory disease, pregnancy, tumor, and ovarian cysts (ruptured or not). In this age group, a rectal-abdominal examination or pelvic examination should be performed. Congenital obstruction of the vagina or uterus (eg, hematometrocolpos) should be considered in the adolescent girl who has not reached menarche but has monthly abdominal pain.

A detailed menstrual and sexual history should be obtained, ideally at a time when the patient's parents are not present. Ultrasound to evaluate gynecologic diagnoses may be indicated when the history and physical examination are not clear. This examination is preferred over an abdominal CT scan for adolescent girls in part because of its greater ability to detect gynecologic conditions.14 A pregnancy test is mandatory for all postmenarchal females.

SCORING SYSTEMS

Scoring systems have been developed in an attempt to increase the diagnostic accuracy through grading features of the history, physical examination, and laboratory tests. To date, no scoring system has been developed that substantially improves the diagnostic accuracy of an experienced examiner. Despite their limitations, scoring systems can be useful for individual patients with appendicitis because they focus attention on key aspects of the evaluation.

One of the most frequently used scoring systems is the Alvarado scoring system.25 It was developed from a large cohort of mainly adult patients with appendicitis. This system identifies eight variables associated with appendicitis and weights each of them for their relative value in diagnosing appendicitis. These variables include migration of pain from a periumbilical location to the right lower quadrant; anorexia; nausea, vomiting, or both; tenderness in the right lower quadrant; rebound tenderness; elevation of the temperature; leukocytosis; and shift to the left for the white blood cell count. The relative score given to each of these is shown in the table.

This scoring system has been given the acronym MANTRELS, based on its components. The MANTRELS score has been tested in a large group of children presenting with abdominal pain. With the use of a cutoff value of 7, its sensitivity and specificity improve as the age of the child increases. Patients who are 16 or 17 years old and who have a score of 7 have a 100% sensitivity and a 93% specificity for having appendicitis. In other age groups, the value of this score is more limited.26 Other studies have also shown that the scoring system has limited value for patients in whom appendicitis is difficult to diagnose. In particular, the accuracy of the MANTRELS score is not as great in women as it is in men, most likely due to the larger number of diagnoses that can generate right lower quadrant abdominal findings in females.27 Despite these limitations, the MANTRELS score is a convenient method to use when evaluating children with suspected appendicitis. Components of this scoring system serve as a useful checklist of symptoms and signs to investigate and as a useful teaching tool for medical students and residents.

DIFFERENTIAL DIAGNOSIS

A wide range of diagnoses can be confused with appendicitis. Because most children who present with acute abdominal pain do not undergo laparotomy or another definitive test, the final diagnosis is most often based on clinical criteria alone. Among children evaluated in the emergency department, the most frequent diagnosis is abdominal pain, followed by gastroenteritis (Fig. 2).2 For children undergoing appendectomy who are not found to have appendicitis, the most common final pathologic diagnosis is mesenteric adenitis or gastroenteritis.27 Approximately 7% of children who are evaluated for acute abdominal pain will return for medical evaluation within 10 days. Among these patients, 29% will be given a new diagnosis based on repeat assessment.3 For these reasons, either a repeat evaluation or telephone follow-up is recommended.

Table

TABLEComponents of the MANTRELS Score Used for Diagnosing Acute Appendicitis and General Recommendations*

TABLE

Components of the MANTRELS Score Used for Diagnosing Acute Appendicitis and General Recommendations*

TREATMENT

The treatment of simple, uncomplicated appendicitis is appendectomy. In simple cases, this procedure carries little morbidity and is associated with only a 1- to 2-day hospital stay. Hospitalization is mainly needed for pain management and intravenous hydration until the child is taking sufficient fluids. Open appendectomy remains the standard procedure with which laparoscopic appendectomy is compared. One prospective study showed that children who underwent the laparoscopic procedure had less postoperative pain and a shorter hospital stay than did those who underwent open appendectomy, but differences were small.28 Reusable instruments and shorter operative times that come with more experience can reduce the cost of the more expensive laparoscopic procedure.29 Because most children can easily undergo appendectomy through a single small incision, some pediatric surgeons have been selective in applying the laparoscopic procedure. Laparoscopic appendectomy may be advantageous for obese children, who generally require a larger incision when using an open approach, or for children in whom the diagnosis of appendicitis is in doubt, especially adolescent girls.

Figure 2. Final diagnoses given for children being evaluated for acute abdominal pain. UTI = urinary tract infection. (Data from Reynolds SL, )affe DM. Diagnosing abdominal pain in a pediatric emergency department. Pediatr Emerg Care. 1992;8:126-128.)

Figure 2. Final diagnoses given for children being evaluated for acute abdominal pain. UTI = urinary tract infection. (Data from Reynolds SL, )affe DM. Diagnosing abdominal pain in a pediatric emergency department. Pediatr Emerg Care. 1992;8:126-128.)

When children present with perforation accompanied by a right lower quadrant abscess and only right lower quadrant peritoneal irritation, interval appendectomy may be preferred. With this strategy, a percutaneous drain is placed under CT scan guidance to initially drain the abscess. After a course of intravenous antibiotics and several weeks, the child undergoes appendectomy. This approach is ideal when the child is not toxic but presents with right lower quadrant pain associated with abscess, with or without leukocytosis. A peripherally inserted central catheter may be placed for the administration of antibiotics in the hospital and later at home. Most parents have little difficulty giving antibiotics at home, despite their initial reluctance, and prefer this to continued hospitalization. Children who have a perforation require longer hospital stays than do those with simple appendicitis. Children remain in the hospital until they are afebrile, their abdominal pain and opioid requirement have decreased, and they are able to take sufficient fluids. A peripherally inserted central catheter can be used to continue intravenous antibiotics at home and allow early discharge.

CONCLUSION

The diagnosis of appendicitis in children is primarily based on history and physical examination. Select adjunct laboratory tests and imaging studies can assist, but have a limited role. Awareness of the typical and atypical patterns of presentation of appendicitis, particularly in younger children and adolescent girls, is essential for those evaluating children with acute abdominal pain. Early recognition and prompt surgery are essential for reducing the morbidity of this common disease.

REFERENCES

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12. Rothrock SG, Green SM Hummel CB. Plain abdominal radiography in the detection of major disease in children: a prospective analysis. Ann Emerg Med. 1992;21:1423-1429.

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14. Cohen HL, Smith WL, Kushner LXZ, et al. Imaging evaluation of acute right lower quadrant and pelvic pain in adolescent girls. American College of Radiology. ACR Appropriateness Criteria. Radiology. 2000;215:833-840.

15. Roosevelt GE, Reynolds SL. Does the use of ultrasonography improve the outcome of children with appendicitis? Acad Emerg Med. 1998;5:1071-1075.

16. Reich JD, Brogdon B, Ray WE, Eckert J, Gorell H. Use of CT scan in the diagnosis of pediatric acute appendicitis. Pediatr Emerg Care. 2000;16:241-243.

17. Emil S, Mikhail P, Laberge JM et al. Clinical versus sonographic evaluation of acute appendicitis in children: a comparison of patient characteristics and outcomes. / Pediatr Surg. 2001;36:780-783.

18. Barker AP, Davey RB. Appendicitis in the first three years of life. Aust NZJ Surg. 1988;58:49M94.

19. Rappaport WD, Peterson M, Stanton C Factors responsible for the high perforation rate seen in early diildhood appendicitis. Am Surg. 1989;55:602-605.

20. Williams N, Kapila L. Acute appendicitis in the under-5 year old. J R Coll Surg Edinb. 1994;39:168-170.

21 . Horwitz JR, Gursoy M, Jaksic T, Lally KP. Importance of diarrhea as a presenting symptom of appendicitis in very young children. Am J Surg. 1997;173:80-82.

22. Nance ML, Adamson WT, Hedrick HL. Appendicitis in the young child: a continuing diagnostic challenge. Pediatr Emerg Care. 2000;16:160-162.

23. Cappendijk VC, Hazebroek FW. The impact of diagnostic delay on the course of acute appendicitis. Arch Dis Child. 2000;83:64-66.

24. Rothrock SG, Green SM, Dobson M, Colucciello SA, Simmons CM Misdiagnosis of appendicitis in nonpregnant women of childbearing age. / Emerg Med. 1995;13:1-8.

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26. Bond GR, Tully SB, Chan LS, Bradley RL. Use of the MANTRELS score in childhood appendicitis: a prospective study of 187 children with abdominal pain. Ann Emerg Med. 1990;19:1014-1018.

27. Owen TD, Williams H, Stiff G, Jenkinson LR, Rees BI. Evaluation of the Alvarado score in acute appendicitis. / R Soc Med. 1992;85:87-88.

28. Lintula H, Kokki H, Variamo K. Single-blind randomized clinical trial of laparoscopic versus open appendicectomy in children. Br J Surg. 2001;88:510-514

29. Canty TG, Collins D, Losasso B, Lynch F, Brown C. Laparoscopic appendectomy for simple and perforated appendicitis in children: the procedure of choice? J Pediatr Surg. 2000;35:1582-1585.

TABLE

Components of the MANTRELS Score Used for Diagnosing Acute Appendicitis and General Recommendations*

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