Sweat Glands: Structure & Pathology
Human skin possesses two distinct types of sweat glands, differing in location, secretion method, and function.
Comparison: Eccrine vs. Apocrine
| Feature | Eccrine Glands | Apocrine Glands |
|---|---|---|
| Distribution | Almost everywhere (high on palms/soles) | Axilla, groin, areola (specialized areas) |
| Secretion | Watery, dilute, electrolyte-rich | Viscous, odorous (lipid/protein-rich) |
| Connection | Directly to the skin surface | Connect to hair follicles |
| Function | Thermoregulation | Pheromonal/scent |
Related Clinical Disorders
- Miliaria (Heat Rash): Caused by blockage of eccrine ducts.
- Miliaria crystallina: Superficial (stratum corneum) blockage.
- Miliaria rubra: Deeper (epidermal) blockage; “prickly heat.”
- Hidradenitis Suppurativa: A chronic, inflammatory disease of the apocrine-bearing skin (axilla/groin). Characterized by recurrent nodules, abscesses, and sinus tracts.
- Bromhidrosis: Foul-smelling sweat, usually caused by bacterial breakdown of apocrine secretions.
High-Yield Exam Pearl:
- Eccrine vs. Apocrine: Remember that eccrine glands are for cooling, while apocrine glands are associated with hair follicles and odor.
- Hidradenitis Suppurativa: This is a disease of the follicular unit in apocrine areas, *not* a primary infection of the gland itself.