What is the proper way to chart purpura on a physical examination (PE)?

Proper Documentation of Purpura on Physical Examination

When documenting purpura on physical examination, you should record the morphology, distribution, palpability, size, and color of lesions on a body map, estimating the percentage of body surface area involved.

Key Documentation Elements

1. Morphology and Classification

• Document whether the purpura is:
  • Nonbranching (round/oval) vs. branching (retiform) 1
  • Palpable vs. non-palpable 2, 3
  • Associated with other skin findings (blisters, erosions, necrosis) 2

2. Distribution Pattern

• Record the specific anatomical location using a body map 2
• Note whether distribution is:
  • Dependent (gravity-dependent areas)
  • Acral (extremities)
  • Generalized
  • Symmetric vs. asymmetric 1

3. Quantification

• Estimate percentage of body surface area (BSA) involved using the Lund and Browder chart 2
• Document the extent on a body map schematic 2
• Record size of individual lesions (in mm or cm)

4. Associated Features

• Note presence of:
  • Mucous membrane involvement 2
  • Epidermal detachment or Nikolsky sign 2
  • Necrosis or eschar formation 4
  • Surrounding erythema 4
  • Livedo reticularis pattern 4

Documentation Example

SKIN: Purpuric lesions noted on [specific anatomical locations]. Lesions are [palpable/non-palpable], [nonbranching/branching (retiform)], [size range in mm/cm], and [color description]. Distribution is [dependent/acral/generalized/symmetric/asymmetric]. Approximately [X%] BSA involved. [Present/absent] associated findings include [mucous membrane involvement, epidermal detachment, necrosis, surrounding erythema]. Body map completed to document distribution.

Clinical Significance

The morphology of purpura provides important diagnostic clues:

• Nonbranching dependent purpura typically indicates leukocytoclastic vasculitis (e.g., IgA vasculitis) 1
• Branching (retiform) purpura suggests microvascular occlusion with higher mortality risk (~50%) 1
• Palpable purpura is the hallmark of cutaneous vasculitis 5, 3

Common Pitfalls to Avoid

1. Failing to distinguish between palpable and non-palpable purpura, which have different diagnostic implications 2, 3
2. Not documenting the distribution pattern, which helps differentiate between various causes 1
3. Omitting a body map to record the extent and pattern of involvement 2
4. Neglecting to estimate the percentage of body surface area affected 2
5. Overlooking associated features that may suggest specific diagnoses 2, 4

By thoroughly documenting these characteristics of purpura, you provide valuable information that can guide diagnosis, treatment decisions, and assessment of disease progression.