Understanding "Hierarchy" in Dermatology
The term "hierarchy" in dermatology does not refer to a single, standardized medical concept but rather encompasses several contextual meanings depending on the specific application within the field.
Primary Interpretations of Hierarchy in Dermatology
1. Disease Burden Hierarchy and Resource Allocation
The hierarchy of dermatological conditions is often defined by their global disease burden, measured in disability-adjusted life-years (DALYs), though clinical practice guideline (CPG) development does not consistently align with this burden. 1
- Melanoma and keratinocyte cancers receive disproportionately greater representation in CPGs compared to their actual disease burden as measured by DALYs, particularly driven by high-income countries 1
- Under-represented conditions relative to their disease burden include acne, alopecia areata, cellulitis, and scabies, despite their significant global impact 1
- Appropriately represented conditions include urticaria, atopic dermatitis, and contact dermatitis, which show proportional alignment between CPG representation and DALY metrics 1
The coefficient of determination (R² = 0.1676) demonstrates overall poor correlation between the number of CPGs produced and the actual global disease burden, indicating that hierarchy in resource allocation does not follow disease impact 1
2. Structural Hierarchy of Skin Anatomy
In dermatological education and practice, hierarchy refers to the layered anatomical organization of the skin, which is fundamental to understanding pathology and treatment approaches 1:
Epidermis (outermost layer): Contains multiple strata from deepest to most superficial:
- Stratum basale (germinativum)
- Stratum spinosum
- Stratum granulosum
- Stratum lucidum (only in thick skin)
- Stratum corneum 1
Dermis (middle layer): Comprises approximately 90% of skin thickness, containing blood vessels, lymph vessels, hair follicles, sweat glands, sebaceous glands, and nerve endings 1
Subcutaneous tissue/hypodermis (deepest layer): Contains adipose tissue and provides structural support 1
3. Clinical Priority Hierarchy
Dermatological manifestations can be hierarchically classified by their clinical urgency and impact on morbidity and mortality 2, 3:
- Life-threatening dermatological conditions requiring immediate intensive care: Stevens-Johnson syndrome/toxic epidermal necrolysis, angioinvasive fungal infections, acute graft-versus-host disease, calciphylaxis 2, 3
- Dermatological manifestations associated with systemic diseases where skin lesions indicate underlying critical pathology 2
- Secondary dermatological manifestations from ICU management (infectious or allergic origin) 2
- Pre-existing dermatological conditions unrelated to the critical process 2
4. Subspecialty Hierarchy and Role Definition
Dermato-oncology represents an emerging hierarchical subspecialty within dermatology, reflecting the increasing specialization required for managing complex skin cancers 4:
- Dermatologists play a central role across the entire spectrum of skin cancer management: prevention, diagnosis, treatment coordination, multidisciplinary team leadership, and follow-up 4
- The field has evolved from symptom control to targeted, personalized therapy based on molecular and biological understanding of disease processes 5
Common Pitfalls
- Assuming CPG availability reflects disease importance: The geographic and disease-specific distribution of dermatology CPGs is heavily skewed toward high-income countries (72.1% from high-SDI countries) and does not correlate with global disease burden 1
- Overlooking resource disparities: Europe and North America produce 73% of dermatology CPGs, while Asia contributes only 15.5%, South America 4.9%, and Africa has no representation 1
- Ignoring funding transparency: Approximately 39.4% of dermatology CPGs fail to provide funding statements, and 8% declare pharmaceutical company funding, which may influence hierarchical prioritization of conditions 1