Stature Abnormal: Tall Stature and Short Stature

Introduction

Understanding abnormal stature is crucial for success in the MCCQE1 exam and for providing excellent pediatric care in the Canadian healthcare system. This comprehensive guide will cover both tall and short stature, focusing on Canadian guidelines and practices to help you prepare effectively for your MCCQE1.

Definitions and Epidemiology

Tall Stature

Tall stature is defined as height above the 97th percentile for age and sex or more than 2 standard deviations above the mean.

Short Stature

Short stature is defined as height below the 3rd percentile for age and sex or more than 2 standard deviations below the mean.

Etiology

Diagnostic Approach

Canadian Guidelines for Evaluation and Management

The Canadian Paediatric Society provides specific guidelines for the evaluation and management of abnormal stature:

1. Referral Criteria: Children with height <3rd or >97th percentile should be referred to a pediatric endocrinologist.

2. Growth Monitoring: Regular height and weight measurements should be plotted on appropriate growth charts for Canadian children.

3. Investigations: The extent of investigations should be guided by clinical findings and suspicion of underlying pathology.

4. Treatment: Management should be individualized based on the underlying cause and may include:

   • Hormonal therapy (e.g., growth hormone for GH deficiency)
   • Treatment of underlying conditions (e.g., celiac disease, hypothyroidism)
   • Psychosocial support and counseling

Key Points to Remember for MCCQE1

• 🔑 Familiarize yourself with the Canadian growth charts and percentiles
• 🔑 Know the common causes of abnormal stature in the Canadian population
• 🔑 Understand the diagnostic approach, including appropriate investigations
• 🔑 Be aware of the Canadian guidelines for referral and management
• 🔑 Recognize the psychosocial impact of abnormal stature on children and families

Sample MCCQE1-Style Question

# Sample Question

A 14-year-old boy presents with concerns about his height. He is 190 cm tall (above 99th percentile) and has a arm span-to-height ratio of 1.05. His father is 185 cm and his mother is 170 cm tall. Which one of the following is the most appropriate next step in management?

- [ ] A. Reassure the patient and family that this is likely constitutional tall stature
- [ ] B. Order a karyotype to rule out Klinefelter syndrome
- [ ] C. Refer to a pediatric endocrinologist for further evaluation
- [ ] D. Perform a wrist X-ray for bone age assessment
- [ ] E. Start treatment with testosterone to accelerate epiphyseal closure

Explanation

The correct answer is:

• C. Refer to a pediatric endocrinologist for further evaluation

This patient's height is above the 99th percentile, and he has an increased arm span-to-height ratio, which is suggestive of Marfan syndrome. While constitutional tall stature is possible, the extreme height and increased arm span warrant further investigation. In line with Canadian guidelines, children with height above the 97th percentile should be referred to a pediatric endocrinologist for comprehensive evaluation.

Option A is incorrect as reassurance without further evaluation would be inappropriate given the clinical findings. Option B (karyotype) might be considered but is not the most appropriate next step. Option D (bone age assessment) may be part of the workup but should be ordered by the specialist. Option E (testosterone treatment) is not indicated without a clear diagnosis and could be harmful.

References

1. Canadian Paediatric Society. (2020). A guide to pediatric growth and development. Retrieved from https://www.cps.ca/en/documents/position/guide-to-pediatric-growth-and-development (opens in a new tab)

2. Rogol, A. D., & Hayden, G. F. (2014). Etiologies and early diagnosis of short stature and growth failure in children and adolescents. The Journal of Pediatrics, 164(5), S1-S14.e6.

3. Cohen, P., Rogol, A. D., Deal, C. L., Saenger, P., Reiter, E. O., Ross, J. L., ... & 2007 ISS Consensus Workshop participants. (2008). Consensus statement on the diagnosis and treatment of children with idiopathic short stature: a summary of the Growth Hormone Research Society, the Lawson Wilkins Pediatric Endocrine Society, and the European Society for Paediatric Endocrinology Workshop. The Journal of Clinical Endocrinology & Metabolism, 93(11), 4210-4217.

4. Sotos, J. F., & Argente, J. (2008). Overgrowth disorders associated with tall stature. Advances in Pediatrics, 55(1), 213-254.

5. Canadian Agency for Drugs and Technologies in Health. (2015). Growth Hormone for Treatment of Idiopathic Short Stature: A Review of Clinical Effectiveness, Cost-Effectiveness, and Guidelines. Retrieved from https://www.cadth.ca/growth-hormone-treatment-idiopathic-short-stature-review-clinical-effectiveness-cost-effectiveness (opens in a new tab)