Patient Presentation
A 17-year-old female came to clinic after she had a problem when doing her regular gym routine. She was lying on a mat to do some leg and abdominal exercises and had a sharp or tingling sensation along her left lower rib. When she got up she could see that the rib seemed to be more prominent on the left than the right side. She wasn’t actively moving or pushing on the area when it occurred, she was just moving from her abdomen rolling towards her back. She stated that it felt “weird.” She denied the ribs making a sound when she would breathe, or would push on the rib or try to manipulate the rib. The past medical history showed that she was a former gymnast.

The pertinent physical exam revealed normal vital signs and growth parameters. Her chest wall had a prominence of the lower left ribs laterally around the insertion of the 9th rib into the costal cartilages. There was normal chest wall expansion. The mild pain could be elicited when “hooking” the physician’s fingers under the lower costal cartilages and gently pulling the ribs anteriorly and superiorly. She had a normal abdominal examination.

The diagnosis of slipping rib syndrome was made. She was advised that she could rest and use some ibuprofen in the short term, and a referral to physical therapy was made. At followup with her regular physician, she did not have any abnormal position of the ribs and was having only intermittent discomfort that was random but easily managed with rest. “The physical therapy really seems to help and is making my core muscles very strong,” she noted.

Discussion
There are 12 pairs of ribs that attach posterior to the thoracic vertebrae by the costovertebral joints. Anteriorly ribs 1-7 (true ribs) attach directly to the sternum and ribs 8-10 (false ribs) attach indirectly to the sternum though the costal cartilage. Ribs 11-12 are floating ribs as they do not attach to the sternum.

Slipping rib syndrome (SRS) occurs when there is laxity of the attachments of the anterior sterno-costal structures allowing rib hypermobility which can cause pain. Although any rib can have this problem, ribs 8-10 are classically involved as these are attached to the sternum by a relatively larger cartilaginous structure. In children the attachment is a cartilaginous cap and is a fibrous band in adults. SRS can cause discrete localized pain, stinging or other types of sensations and often is worse with particular movements which recreate the rib subluxation such as the hooking maneuver described above. The rib can be in an abnormal position or can cause a popping or cracking sound/sensation. True neurological problems are not common. Some patients will some describe chest pain or abdominal pain and therefore SRS may not be considered and may undergo unnecessary evaluation and treatment can be delayed. In one study, athletes, who are more likely to get SRS, had pain for 15 months before being diagnosed. The most common athletic activity associated with pain onset was no activity in the same study. SRS is more common in female patients and usually is unilateral but can be bilateral.

Learning Point
Reassurance that SRS is a benign syndrome can greatly help patients. However some patients will have intense pain and therefore do not have a benign course. Short term relief interventions usually are recommended.
Common other treatment can include:

• Rest, ice, massage
• Short course of oral pain reliever
• Diclofenac gel
• Physical therapy and/or osteopathic manipulative treatment
• Nerve block
• Botulinum toxin injection
• Surgery – excision or plating of costal cartilage

Questions for Further Discussion
1. What anatomical rib variations can cause pain? A review can be found here
2. Who is more at risk for spontaneous pneumothorax?
3. What are indications for surgical treatment of pectus excavatum or carinatum?

Related Cases

Disease: Slipping Rib Syndrome | Chest Injuries and Disorders

Symptom/Presentation: Chest Pain

Specialty: General Pediatrics | Orthopaedic Surgery and Sports Medicine | Physical Medicine and Rehabilitation / Physical Therapy

Age: Teenager

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for this topic: Chest Injuries and Disorders

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Bonasso PC, Petrus SN, Smith SD, Jackson RJ. Sternocostal slipping rib syndrome. Pediatr Surg Int. 2018;34(3):331-333. doi:10.1007/s00383-017-4221-1

Foley CM, Sugimoto D, Mooney DP, Meehan WPI, Stracciolini A. Diagnosis and Treatment of Slipping Rib Syndrome. Clinical Journal of Sport Medicine. 2019;29(1):18. doi:10.1097/JSM.0000000000000506

MacGregor RM, Schulte LJ, Merritt TC, Keller MS, Aubuchon JD, Abarbanell AM. Slipping Rib Syndrome in Children: Natural History and Outcomes Following Costal Cartilage Excision. J Surg Res. 2022;280:204-208. doi:10.1016/j.jss.2022.06.061

Author
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa

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Patient Presentation
A 12-year-old female came to clinic for her health maintenance examination. She had been well overall. She had menarche about 10 months previously and had had three periods of time where she had had bleeding for 3 weeks. The last time only stopped with hormonal intervention. She had been at the 95% for weight last year and had increased her body mass index significantly over the subsequent year. The previous year she had had some abdominal striae but did not have any acanthosis nigricans. Laboratory testing for obesity, insulin resistance, and thyroid disease were negative last year.

The past medical history was otherwise negative. Her review of systems was negative for sleeping problems including snoring, problems with fatigue, headache, musculoskeletal problems, or bruising or bleeding.

The pertinent physical exam showed normal vital signs. Her BMI was 36.2 (~120% for the usual 95%). Her blood pressure was 110/74. Her skin examination showed acanthosis nigricans at her neck and truncal striae. She had increased general hair on her body that looked to be consistent with the family and her genetic background. The rest of her examination was normal.

The diagnosis of a healthy female with increased obesity, abnormal menstrual bleeding and acanthosis nigricans was made. Polycystic ovarian syndrome (PCOS) was considered. Her hemoglobin A1c was 5.7%, she had increased triglycerides, HDL and LDL cholesterol on fasting sample. Testosterone was normal as was testing for bleeding disorders.

The patient’s clinical course showed that she was able to see an endocrinologist who felt that she was likely at risk for PCOS but at this time could not make that diagnosis. She did have increased obesity, dyslipidemia and insulin resistance. She was started on metformin, life-style changes and had nutritional counseling. She was to followup in 6 months.

Discussion
Metformin (1,1-dimethylbiguanide), while not perfect, is a pretty good medication. It has been in use in the United Kingdom since 1958 and in the United States since 1995. It is considered a generally safe drug. It is inexpensive, orally absorbed, not metabolized by the liver, and is not highly protein bound. It does not cause hypoglycemia. It is excreted unchanged mainly through the kidney, therefore patients with renal failure need to be monitored closely. Side effects include nausea and emesis (which are much improved when taken with a meal). Lactic acidosis is rare (incidence 1 in 30,000). Metformin can cause decreased B12 levels as well. Monitoring of pre- and post-prandial glucoses, Hemoglobin A1c, renal function and B12 levels are recommended at intervals.

Metformin, by several interactions but mainly by activating AMP-activated protein kinase (AMPK) causes:

• Decreases glucose intestinal absorption
• Decreases hepatic gluconeogenesis
• Opposes glucagon
• Increases whole-body insulin sensitivity though increased insulin activity

Patients (50-70%) with PCOS have insulin resistance and metformin is a common medication used for this. Additionally metformin also has favorable effects on sex hormones and sex-hormone binding globulin which also helps treat the oligomenorrhea of PCOS. A review of PCOS and its potential health problems can be found here.

Learning Point
Indications and common off label uses of metformin include:

• Type 2 diabetes mellitus (T2DM) – first line therapy
• Prediabetes
• Type 1 diabetes mellitus – not for treatment but sometimes is used as adjuvant therapy
• Gestational diabetes
• PCOS
• Weight gain issues due to antipsychotic medications

Other potential uses:

• Anti-cancer properties for decreased risk of cancer overall and particular gastointestinal and genital cancers
• Anti-aging
• Cardiovascular protective agent
• Neuroprotective agent – uses with dementia and psychiatric disease
• Liver disease – metabolic dysfunction-associated steatotic

Use of metformin for obesity and weight reduction has positive effect but data only shows small effects. A 2016 Cochrane systematic review concluded “…that pharmacological interventions (metformin, sibutramine, orlistat and fluoxetine) may have small effects in reduction in BMI and obesity in obese children and adolescents. The review notes that many of the drugs are not licensed for this indication, some of the drugs have been withdrawn, and many of the studies are of low quality.” A 2021 systematic review concluded “…that metformin has modest but favorable effects on weight and insulin resistance and a tolerable safety profile among children and adolescents with obesity.” The authors note that the “”…evidence is of varying quality, with high heterogeneity between trials….”

Questions for Further Discussion
1. What counseling do you emphasize for patients with obesity?
2. When do you prescribe metformin in your practice and why?
3. What are indications of insulin resistance?

Related Cases

Disease: Metformin | Metabolic Syndrome | Polycystic Ovary Syndrome

Symptom/Presentation: Bleeding and Bruising | Obesity | Health Maintenance and Disease Prevention

Specialty: Endocrinology | Obstetrics / Gynecology | Pharmacology / Toxicology

Age: School Ager

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for these topics: Metabolic Syndrome and PCOS.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Mead E, Atkinson G, Richter B, et al. Drug interventions for the treatment of obesity in children and adolescents. Cochrane Database Syst Rev. 2016. Accessed April 15, 2025.

Wang YW, He SJ, Feng X, et al. Metformin: a review of its potential indications. Drug Des Devel Ther. 2017;11:2421-2429. doi:10.2147/DDDT.S141675

Masarwa R, Brunetti VC, Aloe S, Henderson M, Platt RW, Filion KB. Efficacy and Safety of Metformin for Obesity: A Systematic Review. Pediatrics. 2021;147(3):e20201610. doi:10.1542/peds.2020-1610

Karavanaki K, Paschou SA, Tentolouris N, Karachaliou F, Soldatou A. Type 2 diabetes in children and adolescents: distinct characteristics and evidence-based management. Endocrine. 2022;78(2):280-295. doi:10.1007/s12020-022-03172-y

Corcoran C, Jacobs TF. Metformin. In: StatPearls. StatPearls Publishing; 2025. Accessed April 15, 2025. http://www.ncbi.nlm.nih.gov/books/NBK518983/

Petrie JR. Metformin beyond type 2 diabetes: Emerging and potential new indications. Diabetes Obes Metab. 2024;26 Suppl 3:31-41. doi:10.1111/dom.15756

Author
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa

Patient Presentation
While sitting in clinic, a pediatrician noticed that all the medical students and residents were filing into a patient room, and then filed out a few minutes later. She asked her colleague what was so interesting with the patient. “Oh, a 6-month-old male has a solitary mastocytoma and none of the learners had seen one. The Darier sign was really good for them to see and the baby was fine. The mom was happy to know what it was,” she replied.

Discussion
Mastocytosis is group of diseases where there is pathological accumulation of mast cells in different tissues. Cutaneous involvement is one of the most common, but other tissues can include bone marrow, gastrointestinal tract, lymph nodes, liver, or spleen. Systemic mastocytosis usually also has some cutaneous involvement.

Cutaneous involvement has three subtypes:

• Solitary (1-3 lesions) – 10-15%
• Maculopapular cutaneous mastocytosis also called urticaria pigmentosa – most frequent form, 70-80% of children
• Diffuse cutaneous mastocytosis – 5-13%

Mastocytosis overall has a prevalence of 9 per 100,000 persons. In the pediatric age group about 80% have cutaneous mastocytosis. Most patients present in infancy especially the first year, especially the first 6 months. Mastocytosis is associated with the c-KIT gene which regulates stem cell division and activation mutations which result in abnormal proliferation of melanocytes and mast cells.

Diagnosis is clinical but serum tryptase can be elevated in systemic mastocytosis and can assist in diagnosis. Serum tryptase is normal in cutaneous mastocytosis. Biopsy usually is not needed but can be helpful if the diagnosis is in doubt. Most patients are treated symptomatically with avoidance of triggers (see below) and antihistamines as mainstays. Long term most patients (80%) have resolution or minimization of their lesions and symptoms by puberty.

Learning Point
The presentation of the cutaneous lesions can be variable but often are:

• Round or oval shape
• 1-5 cm in diameter
• Red-brown, yellow brown in color
• Indurated and/or erythematous
• Leathery or peau d’orange appearance and/or consistency
• Margins are sharp or indistinct

An image search of cutaneous mastocytosis can be found here.

When rubbed or irritated they can degranulate and release histamine and other vasoactive mediators producing an urticarial reaction with erythema, edema and elevation and/or pruritis of the lesion and surrounding area. This reaction is termed Darier sign. Darier sign is often considered pathognomic but it can also be seen sometimes in juvenile xanthogranuloma or cutaneous lesions of acute lymphocytic leukemia. An absent Darier sign does not exclude cutaneous mastocytosis either. An image search of Darier Sign can be found here.

Patients can present with pruritis, flushing, and urticaria of the lesions. Some families will say that the size of the lesion varies. With more aggressive lesions, blistering can occur. Triggers usually are mechanical irritation of the lesion, trauma, physical exercise, various food/drink ingestion (e.g. spicy foods, hot beverages), temperature changes (e.g. showers, pools, etc.) medications (anti-inflammatory, antibiotics, opiates, contrast, etc.) and venom such as hymenoptera stings. Anaphylaxis is very uncommon but more likely with systemic mastocytosis. Rarely occurring but oncological progression can happen with systemic mastocytosis. Systemic mastocytosis may present with other problems such as organomegaly, organ pain, organ failure, and problems such as tachycardia or syncope which are part of not full-blown anaphylaxis as well.

Additional information about mast cell disorders can be found here

Questions for Further Discussion
1. What is histiocytosis?
2. What causes brown skin lesions? A review can be found here
3. What causes red skin lesions? A review can be found here
4. How do you treat anaphylaxis?

Related Cases

Disease: Cutaneous Mastocytoma | Skin Pigmentation Disorders

Symptom/Presentation: Pigmentary Lesions

Specialty: Dermatology

Age: Infant

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for this topic: Skin Pigmentation Disorders

To view current news articles on this topic check Google News.

To view videos related to this topic check YouTube Videos.

Schenck OL, Blechman AB, Kaley JR, Greer KE. Large hyperpigmented plaques on the trunk of a newborn. Cutis. 2017;99(4):230;261;264.

Leung AKC, Lam JM, Leong KF. Childhood Solitary Cutaneous Mastocytoma: Clinical Manifestations, Diagnosis, Evaluation, and Management. Curr Pediatr Rev. 2019;15(1):42-46. doi:10.2174/1573396315666181120163952

Der Sarkissian SA, Sebaratnam DF. Darier sign in mastocytoma. Medical Journal of Australia. 2021;214(5):206-206. doi:10.5694/mja2.50947

Popadic S, Lalosevic J, Lekic B, Gajic-Veljic M, Bonaci-Nikolic B, Nikolic M. Mastocytosis in children: a single-center long-term follow-up study. Int J Dermatol. 2023;62(5):616-620. doi:10.1111/ijd.16612

Author
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa