# Clinical Cases: Nutrition and Feeding

## Case 1: Failure to Thrive - Inadequate Intake

### Patient Demographics
- **Age:** 4-month-old female
- **Sex:** Female

### Chief Complaint
"My baby isn't gaining enough weight."

### History of Present Illness
A 4-month-old exclusively breastfed female is brought in by her first-time mother for a weight check. The infant's weight has plateaued over the past 6 weeks and has fallen from the 35th percentile at 2 months to below the 5th percentile. Mother reports the baby feeds frequently (every 1-2 hours) for about 5-10 minutes per breast but seems to tire easily and falls asleep at the breast. She has been supplementing with 1-2 oz of pumped breast milk after some feeds but is unsure if the baby is getting enough. The baby has 4-5 wet diapers and 2-3 small yellow stools daily (decreased from newborn period). Mother denies any vomiting, diarrhea, fever, or irritability. The infant was born at term with birth weight of 3.2 kg.

### Growth Parameters
- **Birth weight:** 3.2 kg (35th percentile)
- **Current weight:** 4.6 kg (<5th percentile, weight-for-age z-score -2.1)
- **Length:** 60 cm (25th percentile)
- **Head circumference:** 40 cm (25th percentile)
- **Weight-for-length:** <5th percentile
- **Expected weight at 4 months:** ~6.0-6.5 kg

### Physical Examination
- **General:** Thin-appearing infant, alert but quiet, decreased subcutaneous fat
- **HEENT:** Anterior fontanelle slightly sunken, mucous membranes moist
- **Cardiovascular:** Regular rate, no murmurs
- **Respiratory:** Clear, no distress
- **Abdomen:** Soft, non-tender, no organomegaly, loose skin folds
- **Skin:** Decreased subcutaneous tissue, especially over buttocks and thighs
- **Neurologic:** Appropriate tone, responsive, good eye contact, smiles
- **Developmental:** Age-appropriate (follows face, coos, holds head up)

### Workup
- **CBC:** Normal
- **CMP:** Normal
- **Urinalysis:** Specific gravity 1.025 (concentrated), otherwise normal
- **Pre/post feed weights:** 15 g difference (inadequate milk transfer; expected 60-90 g)
- **Maternal breast examination:** Normal

### Diagnosis
**Failure to thrive due to inadequate caloric intake (breastfeeding difficulty with poor milk transfer)**

### Clinical Reasoning
This infant demonstrates classic failure to thrive with weight <5th percentile, weight crossing downward across percentile lines, and weight-for-length <5th percentile with relative preservation of length and head circumference (indicating caloric rather than chronic or endocrine etiology). The history of short feeding duration, fatigue at breast, and pre/post feed weights showing minimal transfer indicate breastfeeding difficulty. The normal developmental assessment and physical exam argue against underlying organic disease. This is "non-organic" FTT due to inadequate intake.

### Management
1. **Immediate nutritional intervention:**
   - Increase caloric intake with formula supplementation after breastfeeds
   - Target 150-180 kcal/kg/day initially (catch-up growth)
   - Feeding goal: 24-32 oz total daily intake
2. **Breastfeeding support:**
   - Lactation consultant referral
   - Evaluate latch, positioning, milk supply
   - Consider galactagogues if supply issue confirmed
3. **Close monitoring:**
   - Weight check in 48-72 hours, then weekly until gaining appropriately
   - Target weight gain: 20-30 g/day (catch-up growth)
4. **Maternal support:**
   - Screen for postpartum depression
   - Provide encouragement and emotional support
5. **Consider further workup if no improvement:** Sweat chloride, celiac panel, thyroid function

### Clinical Image
![Growth chart showing FTT pattern](case_01_image.jpg)

**Image Description:** WHO growth chart demonstrating the pattern of falling weight percentiles characteristic of failure to thrive.

**Source:** World Health Organization
**URL:** https://www.who.int/tools/child-growth-standards/standards/weight-for-age
**License:** CC BY-NC-SA 3.0

---

## Case 2: Cow's Milk Protein Allergy

### Patient Demographics
- **Age:** 6-week-old male
- **Sex:** Male

### Chief Complaint
"My baby has blood in his stool and is very fussy."

### History of Present Illness
A 6-week-old formula-fed male presents with blood-streaked stools noticed over the past week. Mother reports the infant has been increasingly fussy, especially during and after feeds, with frequent spitting up and what appears to be abdominal discomfort (drawing legs up, crying). Stools have been mucousy and loose with visible streaks of blood. He was switched from breastfeeding to cow's milk-based formula at 2 weeks of age due to maternal medication use. There is no fever, lethargy, or decrease in feeding volume. He is taking 4 oz every 3 hours. Family history is notable for eczema in mother and food allergies in an older sibling.

### Growth Parameters
- **Birth weight:** 3.5 kg (50th percentile)
- **Current weight:** 4.3 kg (35th percentile)
- **Length:** 54 cm (50th percentile)
- **Head circumference:** 37 cm (50th percentile)

### Physical Examination
- **General:** Fussy but consolable infant, mild perianal erythema
- **HEENT:** No oral lesions
- **Cardiovascular:** Normal
- **Respiratory:** Clear
- **Abdomen:** Soft, mildly distended, hyperactive bowel sounds, no masses or hepatosplenomegaly
- **Rectal:** Grossly bloody mucoid stool on diaper, no fissures
- **Skin:** Mild eczematous patches on cheeks and antecubital fossae
- **Neurologic:** Normal tone, age-appropriate reflexes

### Workup
- **Stool studies:**
  - Guaiac: Positive
  - Stool culture: Negative
  - Ova and parasites: Negative
  - Stool reducing substances: Negative
- **CBC:** WBC 12,000, Hgb 11.2, Platelets 380,000, eosinophils 8% (elevated)
- **Stool eosinophils:** Present (on smear)
- **Total IgE:** Mildly elevated
- **CMP:** Normal

### Diagnosis
**Cow's milk protein allergy (non-IgE mediated/food protein-induced allergic proctocolitis)**

### Clinical Reasoning
The presentation of bloody, mucousy stools in a formula-fed infant with fussiness, eczema, family history of atopy, and peripheral eosinophilia is classic for cow's milk protein allergy. The non-IgE mediated form (allergic proctocolitis) typically presents at 2-8 weeks with blood-streaked stools and is more common than IgE-mediated allergy in this age group. The absence of systemic symptoms, adequate growth, and reassuring exam argue against more serious conditions like intussusception, necrotizing enterocolitis, or infectious colitis.

### Management
1. **Dietary elimination:**
   - Switch to extensively hydrolyzed formula (e.g., Alimentum, Nutramigen)
   - If symptoms persist after 2-4 weeks, trial amino acid-based formula (e.g., EleCare, Neocate)
2. **Expected response:**
   - Occult blood may resolve in 72-96 hours
   - Gross blood typically resolves in 1-2 weeks
   - Fussiness improves within 2-4 weeks
3. **Follow-up:**
   - Weight check in 1-2 weeks
   - Clinical reassessment at 4 weeks
4. **Reintroduction:**
   - Can trial milk protein reintroduction at 9-12 months (most outgrow by age 1)
   - Perform in office if IgE-mediated symptoms develop
5. **Parent education:**
   - Avoid introducing cow's milk products in complementary foods
   - Most children outgrow this by 12 months

### Clinical Image
![Bloody stool in CMPA](case_02_image.jpg)

**Image Description:** Photograph of infant stool demonstrating mucus and blood streaks characteristic of cow's milk protein allergy.

**Source:** Wikimedia Commons
**URL:** https://commons.wikimedia.org/wiki/File:Milk_protein_allergy_stool.jpg
**License:** CC BY-SA 4.0

---

## Case 3: Pediatric Obesity

### Patient Demographics
- **Age:** 10-year-old male
- **Sex:** Male

### Chief Complaint
"The school nurse said my son's BMI is too high and he needs to see a doctor."

### History of Present Illness
A 10-year-old male is brought in by his mother after school BMI screening identified him as obese. Mother reports he has always been "big boned" like his father's side of the family. He was average weight as a young child but has gained significantly over the past 3-4 years. His typical day includes skipping breakfast, eating school lunch and often buying extra snacks, drinking 2-3 sodas daily, and eating fast food several times weekly. He plays video games 4-5 hours daily and does not participate in organized sports. He is sedentary at home and is often teased about his weight at school. He snores at night and his mother has noticed pauses in breathing. He denies polyuria, polydipsia, or change in appetite.

### Growth Parameters
- **Height:** 140 cm (60th percentile)
- **Weight:** 58 kg (>99th percentile)
- **BMI:** 29.6 kg/m2 (>99th percentile, z-score +2.5)
- **Blood pressure:** 118/78 mmHg (>95th percentile for age/height = Stage 1 hypertension)

### Physical Examination
- **General:** Obese male, appears stated age
- **HEENT:** Tonsillar hypertrophy 3+, Mallampati class III
- **Neck:** Acanthosis nigricans
- **Cardiovascular:** Normal S1/S2, no murmurs
- **Respiratory:** Clear
- **Abdomen:** Obese, no hepatomegaly palpable, striae
- **Skin:** Acanthosis nigricans at neck, axillae, and groin; striae on abdomen
- **Musculoskeletal:** Mild genu valgum (knock knees)
- **Neurologic:** Normal
- **Tanner staging:** Stage II pubic hair, Stage II genitalia (appropriate for age)

### Workup
- **Fasting glucose:** 108 mg/dL (impaired fasting glucose: 100-125)
- **Fasting insulin:** 32 mIU/L (elevated, indicating insulin resistance)
- **HbA1c:** 5.9% (prediabetes range)
- **Lipid panel:**
  - Total cholesterol: 210 mg/dL (elevated)
  - LDL: 135 mg/dL (elevated)
  - HDL: 38 mg/dL (low)
  - Triglycerides: 185 mg/dL (elevated)
- **AST:** 52 U/L (elevated)
- **ALT:** 68 U/L (elevated)
- **TSH:** 2.8 mIU/L (normal)

### Diagnosis
**Obesity with metabolic syndrome (prediabetes, dyslipidemia, hypertension, suspected NAFLD) and suspected obstructive sleep apnea**

### Clinical Reasoning
This patient has class II obesity (BMI >=120% of 95th percentile) with multiple obesity-related comorbidities: prediabetes (impaired fasting glucose and HbA1c 5.7-6.4%), dyslipidemia, hypertension, elevated transaminases suggesting NAFLD, and symptoms of obstructive sleep apnea. The acanthosis nigricans is a marker of insulin resistance. The normal TSH and height at 60th percentile argue against endocrine causes of obesity. This represents exogenous obesity with serious metabolic consequences requiring comprehensive intervention.

### Management
1. **Lifestyle modification (primary treatment):**
   - Nutrition counseling: Eliminate sugar-sweetened beverages, reduce fast food, portion control, eat breakfast
   - Goal: No more than 1 hour screen time daily, 60 minutes physical activity daily
   - Family-based approach: Whole family dietary changes
2. **Staged weight goals:**
   - Initial: Weight maintenance (will "grow into" weight)
   - Long-term: Gradual weight loss 1-2 lbs/month
3. **Comorbidity management:**
   - Recheck BP in 1-2 weeks (confirm hypertension)
   - Sleep study for OSA evaluation
   - Consider metformin for prediabetes if lifestyle changes insufficient
4. **Monitoring:**
   - Monthly weight checks initially
   - Repeat labs (glucose, lipids, LFTs) in 3-6 months
   - Consider liver ultrasound for NAFLD assessment
5. **Referrals:**
   - Registered dietitian
   - Consider pediatric obesity/weight management program
   - Sleep medicine if OSA confirmed
6. **Mental health support:** Address bullying, self-esteem issues

### Clinical Image
![Acanthosis nigricans](case_03_image.jpg)

**Image Description:** Clinical photograph demonstrating acanthosis nigricans, characterized by dark, velvety skin thickening in the neck folds, a marker of insulin resistance.

**Source:** Wikimedia Commons
**URL:** https://commons.wikimedia.org/wiki/File:Acanthosis_nigricans.jpg
**License:** CC BY-SA 3.0