- Doxycycline is a tetracycline derivative that exhibits excellent penetration into follicles and sebaceous glands.
- Cutaneous glands include the sebaceous, sweat, lacrimal, and mammary glands.
- Sebaceous hyperplasia is common in middle-aged and elderly persons.
- Sebaceous glands develop at puberty in response to androgen stimulation and are attached to the follicle canal by sebaceous ducts.
- Retention of the sebaceous secretions, and dilation of the follicle, may lead to cyst formation.