What are simian creases?

Appeared in: DSSSB 14 August 2024

Explanation

A simian crease is the clinical term for a single, continuous transverse crease that extends across the entire palm of the hand.
It is formed by the fusion of the two normal palmar creases (the heart line and the head line).
While it can occur in the general population, it is found in about 50% of individuals with Down syndrome (Trisomy 21) and is considered a significant clinical marker.
The term 'palmar' directly relates to the palm of the hand, making this option the correct definition.

Option A: This describes Beau's lines, which are horizontal grooves on the nails, not creases on the palm.
Option C: This describes a 'sandal gap' or 'saddle gap', which is a finding on the foot, not the hand.
Option D: This describes cutis verticis gyrata, a condition affecting the scalp, causing it to have a folded or ridged appearance.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Definition and clinical significance of simian crease as background academic context rather than a clinical decision trigger.
The identification of a simian crease during a newborn assessment is a significant finding that prompts the nurse to perform a more detailed examination for other dysmorphic features associated with genetic syndromes like Down syndrome.
It is crucial for nurses to educate parents that a simian crease can also be a normal, isolated finding in a healthy child and does not automatically mean there is an underlying condition.
Patient counseling should be done with sensitivity, explaining that this is one of many signs that are considered together, and further evaluation may be needed to get a complete picture.

How to Approach the Question

First, identify the key term in the question, which is 'simian creases'.
This is a factual recall question that tests your knowledge of clinical terminology.
Analyze the options based on anatomical location. 'Simian' is an older term, but 'crease' refers to a line or fold in the skin.
Evaluate each option: 'nail', 'palmar' (hand), 'toes' (feet), and 'scalp'.
Recall or deduce that 'palmar' refers to the palm of the hand. This makes 'Single transverse palmar creases' the most anatomically plausible answer.
Confirm by eliminating other options which refer to different body parts (nails, feet, scalp) and different clinical signs (Beau's lines, sandal gap, cutis verticis gyrata).

Concept Tested & Keywords

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E6 Anatomy Applied Ashalatha 4e p. 469-471

Practise the full DSSSB 14 August 2024

Attempt every question from this paper in a timed mock, then review the full solution for each one.