Glands 😊

Simplify Clinical Approach

I. Glands Overview

• This section focuses on two main gland types:
• Sweat Glands
• Sebaceous Glands

Sweat Glands

Two types:

• Eccrine → Everywhere → Everytime (At birth)

Gland Classification Based on Mode of Secretion

Signalling Types	Mechanism	Example
Endocrine	Secretory product → bloodstream → distant target cells	Hormones
Autocrine	Secretory product → acts on receptors on the same cell	Platelet Activating Factor (PAF) by platelets → activates same platelets
Paracrine	One cell secretes → acts on nearby cell → Product diffuses	Histamine (ECL cells) → nearby Parietal cells (stimulates acid)
Juxtacrine	Ligand on one cell directly interacts with receptor on other cell ↳ keep α people just near	Transforming growth factor alpha (TGF-α) signalling.

Disorders of Sweat Glands

Miliaria

• Affects: Eccrine glands

• Cause: Blockage of intraepidermal eccrine sweat duct

• Commonest Sweat Gland Disorder

Three types based on blockage level:

• Miliaria Crystallina:



• Blockage: Stratum corneum
• Presentation: Clear, watery vesicles
• usually in infants
• asymptomatic, numerous
• Mnemonic: Crystallina for Corneum

• Miliaria Rubra (Prickly Heat):



• Blockage: Intraepidermal (inside epidermis)
• Presentation: Pruritic, erythematous papules on trunk

• Miliaria Profunda:
• Blockage: Dermoepidermal junction

Fox-Fordyce Disease

• Disorder of: Apocrine glands

• Also known as: Apocrine miliaria

• Onset: Adolescence

• Affects: Females

• Mnemonic: Fox (fox) nu appam (Apocrine) koduthilla, hide (hidradenitis) cheyth vach←

• Pathology: Obstruction in apocrine duct opening

• Presentation:
• Pruritic, skin-coloured papules in apocrine areas
• axilla, groin, nipples

Hidradenitis Suppurativa (HS)

• Also known as: Acne inversa

• affects areas "inverse" to typical acne
• axilla, groins, nipple area

• Mnemonic: Hidradenitis suppurativa → Suppuration that is hidden or adiyil

Patients:

• Onset: Postpubertal age group

• Course: Chronic, remitting, relapsing

• Obese, smokers

• may have diabetes/metabolic syndrome

Pathology:

• Apocrine gland inflammation leading to secondary infection

Lesion progression:

• Polyporus comedones

• Tender papules and pustules

• Painful cysts and abscesses

• Rupture into skin

• Scarring, with typical bridging scars

Treatment (brief):

• Weight loss,

• metabolic syndrome management,

• anti-inflammatory drugs,

• antibiotics,

• retinoids,

• biologicals,

• surgical therapies

Disorders of Sebaceous Glands

Sebaceous Glands

• Secretion Type: Holocrine
• whole cell depleted

• Location: Seborrheic areas
• face
• upper chest
• upper back

• Opens: Into hair follicle

• Development: Activates during adolescence

• Dependent: Androgen dependent

Ectopic Sebaceous Glands

• Occur when sebaceous glands open directly into skin (not hair follicle)

• Mnemonic: My (Meibonian) gland tied (tyson) to manda (montogmery) for (fordyce) sebum (Sebaceous)

Examples:

1. Meibomian glands:
• In eyelids
• Mei → Eye → Eyelids

2. Tyson's gland:
• On prepuce
• Tyson’s → Dick → Prepuce

3. Montgomery tubercles:
• On nipples/areola (mammary area)

4. Fordyce spots:
• Fordyce → Foreplay → Lip and Oral mucosa
• On lips or oral mucosa
• very common
• yellowish, asymptomatic papules

• Important: Different from Fox-Fordyce disease

Acne Vulgaris

• Common disorder of: Sebaceous gland

• Onset: Postpubertal (sebaceous glands become active)

• Polymorphic disorder:
• Various lesion types concurrently
• papules, pustules, comedones, cysts, scars

• Affected sites: Seborrheic areas
• face, upper chest, back

Pathogenesis (four important factors):

1. Sebaceous gland hyperplasia from androgen

2. Increased sebum production

3. duct blockage, comedone formation

4. Altered follicular growth/differentiation

5. Over-colonisation by specific bacteria
• Propionibacterium acnes
• Staphylococcus epidermidis
• Cutibacterium acne

6. Inflammatory mediator release/increased immune response

Newer theory:

• Inflammation is first stage

• Role of hormones,
• especially insulin-like growth factors/insulin

Characteristic lesion:

Comedones

• Blockade of pilosebaceous duct

Variants of Acne:

Hormonal Acne:

• Location: Lower face, typically females

• Association: Other hyperandrogenism signs
• hirsutism, female androgenetic alopecia, increased sebaceous gland discharge

• Rule out: PCOS, SAHA syndrome, HAIR-AN syndrome

• Treatment: Hormonal therapy

Acne Conglobata:

• Severe form

• Presentation:
• Nodules
• abscesses
• severe intercommunicating sinuses

• Usually in: Men, on trunk

• Treatment: Oral retinoids + short course of steroids

• Mnemonic: Congloblata → global acne → severe

Drug-induced Acne (Acneiform Eruptions):

• Presentation: Small monomorphic papules on trunk

• Crucially: No comedones (classical differentiator)

• Seen when: Steroids, anti-tubercular drugs, anti-convulsants
• (Steroid → used for treatment → but cause acne as well)

Acne Excoriée:

• Excoriated acne (patient scratches/picks)

• Rule out: Psychiatric disorder or increased 17-OHP

Grading of Acne:

• Grade 4 Appearance and Rx is INICET favourite

Acne Treatment

ANS

4

Topical Agents

• Topical Retinoids
• 1st line
• Examples: (e.g., tretinoin, adapalene)
• Side Effects:
• Irritation
• Gram-negative folliculitis

• Benzoyl Peroxide
• Side Effects:
• Irritation
• Staining of clothes

• Topical Antibiotics
• Example: Clindamycin

Oral Agents

• Oral Antibiotics
• Examples:
• Doxycycline, Minocycline, Lymecycline

• Oral Retinoids (Isotretinoin)
• Used For:
• Grade 4 acne
• Severe psychological distress from acne
• Mechanism:
• Acts on all four acne pathogenetic mechanisms
• sebum, keratinization, P. acnes, inflammation
• Dosage:
• 0.5–1 mg/kg/day
• Maximum cumulative dose: 120–150 mg/kg
• Most Important Side Effect:
• Teratogenicity
• Contraindicated in women of childbearing age unless:
• Two negative UPTs
• Written contraception advice
• Must be discontinued 3 months before conception
• Other Side Effects:
• Cheilitis (lip inflammation) → m/c
• Severe dryness
• Altered lipid profile
• Hepatotoxic
• Gram-negative folliculitis
• Rarely, psychiatric disturbances

Rosacea

• Also called "acne rosacea":
• Misnomer, not related to acne

• Pathology:
• Inflammation + increased vascular reactivity

• Classical feature:
• Flushing
• sudden redness and discomfort on face
• triggered by sun, hot/spicy food

• Onset: Usually adults

• Location:
• Convexities of face, sparing nasolabial fold

Types of Rosacea:

Key Differentiators from Acne:

• No comedones (blackheads/whiteheads absent)

• Flushing

• Telangiectasias (visible dilated blood vessels)

Treatment

Topical Treatment:

• Metronidazole

Oral Treatment:

• Ivermectin

• Doxycycline

• Other antibiotics

• Low-dose retinoids