Assessment of Nutritional Status in a Child with Unknown Age

Nutritional assessment usually relies heavily on age-dependent indices like Weight-for-Age and Height-for-Age. However, in many developing countries and rural settings, the exact date of birth is often unknown. In such scenarios, age-independent anthropometric indices and clinical signs become critical for identifying malnutrition.

1. Introduction and Challenges

• The Problem of Unknown Age: In communities with low literacy or poor record-keeping, the exact age of a child is often unavailable. This renders standard indices like Weight-for-Age (Gomez, IAP classifications) and Height-for-Age (Waterlow’s stunting) difficult or impossible to calculate accurately.
• Alternative Approaches: Assessment must rely on:
  • Age-independent anthropometric indices: Ratios between different body measurements that remain relatively constant or change predictably regardless of age.
  • Clinical Assessment: Looking for visible signs of wasting and specific nutritional deficiencies.
  • Developmental Assessment: Using milestones to estimate age (though malnutrition itself delays milestones, making this less reliable).

2. Age-Independent Anthropometric Indices

These indicators rely on the principle that in malnutrition, labile tissues like fat and muscle are depleted while static tissues like the skeleton (bones) are relatively preserved. Comparing a labile measure to a skeletal measure provides an index of nutritional status.

A. Weight-for-Height/Length (Wasting)

• Principle: This is the most important indicator for acute malnutrition. A child who is acutely malnourished will weigh less than a healthy child of the same height, regardless of their age.
• Significance: It indicates current nutritional status (wasting). It is independent of age between 1 and 5 years.
• Interpretation (WHO Standards):
  • Normal: -2 SD to +2 SD.
  • Moderate Acute Malnutrition (MAM): Weight-for-height between -2 SD and -3 SD.
  • Severe Acute Malnutrition (SAM): Weight-for-height < -3 SD.
• Classification:
  • Waterlow’s Classification:
    • Normal: >90% of reference median.
    • Mild Wasting: 80–90%.
    • Moderate Wasting: 70–80%.
    • Severe Wasting: <70%.

B. Mid-Upper Arm Circumference (MUAC)

• Principle: Between the ages of 1 and 5 years (some sources say 6 months to 5 years), the mid-upper arm circumference remains relatively constant in healthy children (increasing only slightly). In malnourished children, muscle wasting and fat loss cause a significant reduction in MUAC.
• Method:
  1. Locate the midpoint of the left upper arm between the tip of the shoulder (acromion) and the tip of the elbow (olecranon) with the arm flexed at 90 degrees.
  2. Mark the midpoint.
  3. Measure the circumference at this point with the arm hanging loosely at the side.
  4. Use a non-stretchable tape or a specific tri-colored MUAC tape (Shakir’s tape).
• Interpretation (6 months to 5 years):
  • > 13.5 cm (Green): Normal / Well-nourished.
  • 12.5 cm – 13.5 cm (Yellow): Moderate Acute Malnutrition (MAM).
  • < 12.5 cm (Red): Severe Acute Malnutrition (SAM) according to older guidelines (some sources now use <11.5 cm for SAM and 11.5–12.5 cm for MAM).
  • Current WHO/IMNCI Cut-offs for SAM: < 11.5 cm indicates Severe Acute Malnutrition and high risk of mortality.
• Advantages: Simple, cheap, can be done by health workers, and strongly predicts mortality.

C. Skinfold Thickness

• Principle: Measures subcutaneous fat, which is a calorie reserve. Malnutrition depletes fat stores.
• Sites: Triceps (most common), subscapular, biceps, supra-iliac.
• Method: Using Harpenden or Holtain calipers, a fold of skin and subcutaneous fat is pinched away from the underlying muscle.
• Interpretation: Values < 60% of standard suggest severe depletion of calorie reserves.

D. Body Ratios and Indices

Several ratios have been developed to assess nutrition without age.

1. Quac Stick (Quacker Arm Circumference Stick):

   • A height-measuring stick where height is calibrated against the expected MUAC for that height (instead of cm).
   • Method: The child stands against the stick. The level of their height corresponds to a specific MUAC value (e.g., the 80% or 85% of expected MUAC for that height).
   • Interpretation: If the child's actual measured MUAC is lower than the value indicated by their height on the stick, they are malnourished.

2. Rao and Singh Index (Weight/Height²):

   • Calculation: Weight (kg) / [Height (cm)]².
   • Interpretation:

     • 0.0015: Normal.

     • 0.0013 – 0.0015: Moderate Malnutrition.

     • < 0.0013: Severe Malnutrition.

3. Kanawati and McLaren Index (MUAC/Head Circumference Ratio):

   • Principle: Head circumference is relatively spared in malnutrition, while MUAC decreases.
   • Calculation: Mid-arm Circumference (cm) / Head Circumference (cm).
   • Interpretation:

     • 0.31: Normal.

     • 0.28 – 0.31: Mild Malnutrition.

     • 0.25 – 0.28: Moderate Malnutrition.

     • < 0.25: Severe Malnutrition.

4. Dugdale's Index:

   • Calculation: Weight (kg) / Height (cm)^1.6.
   • Interpretation: < 0.79 indicates malnutrition; > 0.79 is normal.

5. Chest/Head Circumference Ratio:

   • Normal Course: At birth, Head Circumference (HC) > Chest Circumference (CC). By 1 year (ranges 6-12 months), CC equals HC. After 1 year, CC > HC.
   • In Malnutrition: The chest circumference grows slower than the head (which is spared). If CC < HC in a child who visually appears older than 1 year (e.g., has teeth, can walk), it suggests malnutrition.

6. The Bangle Test:

   • A simple field test. A bangle with an internal diameter of 4 cm is slipped up the arm.
   • If it passes above the elbow to the upper arm, it indicates muscle wasting (Severe Malnutrition).

3. Clinical Assessment (Visible Signs)

When age is unknown, clinical signs are paramount for diagnosis, especially for Severe Acute Malnutrition (SAM).

A. Visible Severe Wasting

• Definition: The child looks like "skin and bones."
• Examination:
  • Remove clothes.
  • Look at the shoulders, arms, ribs, buttocks, and thighs.
  • Baggy Pants Appearance: Loose skin folds on the buttocks due to loss of gluteal fat and muscle.
  • Ribs: Easily visible outline.
• Significance: Indicates Marasmus (Severe Wasting).

B. Bilateral Pitting Oedema

• Definition: Accumulation of fluid in tissues, a hallmark of Kwashiorkor.
• Method: Apply gentle thumb pressure on the dorsum of both feet for 3–10 seconds. If a pit (dent) remains after releasing, oedema is present.
• Grading:
  • + (Mild): Both feet.
  • ++ (Moderate): Feet and lower legs/hands.
  • +++ (Severe): Generalized (feet, legs, hands, arms, face).
• Significance: Presence of nutritional oedema automatically classifies the child as having Severe Acute Malnutrition (SAM), regardless of other anthropometric indices.

C. Cutaneous and Appendageal Signs

• Hair:
  • Hypochromotrichia: Loss of pigment (brown/reddish hair).
  • Flag Sign: Alternating bands of light and dark hair reflecting periods of poor and good nutrition.
  • Texture: Sparse, thin, silky, easy to pluck.
• Skin:
  • Crazy Pavement Dermatosis (Flaky Paint Dermatosis): Hyperpigmented patches that desquamate to reveal raw hypopigmented skin (typical of Kwashiorkor).
  • Dryness/Atrophy: Loose, wrinkled skin in Marasmus.
• Facies:
  • Moon Face: Round, swollen face (Kwashiorkor).
  • Monkey Facies (Old Man Look): Loss of buccal fat pads (Marasmus).

D. Vitamin and Mineral Deficiencies (Micronutrients)

• Vitamin A: Night blindness, Bitot’s spots, corneal xerosis/ulceration.
• Iron: Pallor (palms, conjunctiva, tongue), spoon-shaped nails (koilonychia).
• Vitamin D/Calcium (Rickets):
  • Widened wrists and ankles (double malleoli sign).
  • Bow legs (genu varum) or knock knees (genu valgum).
  • Frontal bossing, rachitic rosary (beading of ribs).
• B-Complex: Angular stomatitis, cheilosis, glossitis (magenta/red tongue).

4. Estimating Age (To use Age-Dependent Charts)

If anthropometry requires age (e.g., to confirm stunting), attempts can be made to estimate age using:

• Local Events Calendar: Relating birth to festivals, seasons, or major local events.
• Dental Eruption:
  • 6 months: First lower incisors.
  • 1 year: ~6–8 teeth.
  • 2.5 years: Full set of 20 milk teeth.
  • 6 years: First permanent molar.
• Developmental Milestones:
  • Head holding: 3–4 months.
  • Sitting without support: 8 months.
  • Standing/Walking: 12 months.
  • Note: Malnutrition delays these milestones, so this method may underestimate age (making the child appear younger and potentially better nourished on charts than they actually are).

5. Summary of Classification Without Age

6. Practical Application (IMNCI Protocol)

In the Integrated Management of Neonatal and Childhood Illnesses (IMNCI), assessment of malnutrition does not strictly require age for categorization of severity.

1. Check for Visible Severe Wasting.
2. Look for Oedema of Both Feet.
3. Measure Weight-for-Length/Height (using charts provided in the booklet).
4. Measure MUAC (if child is > 6 months).

Conclusion: Even without a known date of birth, a comprehensive nutritional assessment is possible using weight-for-height, MUAC, and thorough clinical examination for wasting, oedema, and micronutrient deficits. These methods effectively identify children at high risk of mortality who require immediate intervention.

Sources: