Pilosebaceous Unit & Apocrine Disorders

Question 1

4 components of pilosebaceous unit

Answer 1

1) keratinized follicular infundibulum
2) hair
3) sebaceous gland
4) sebaceous duct, which connects gland w/ infundibulum.

Question 2

Overgrowth of which flora causes acne vulgarism?

Answer 2

Propionibacterium acnes

Question 3

Microcomedone

Answer 3

Infundibular hyperkeratosis w/ androgen stimulation of sebum secretion → proliferation / retention of corenocytes. Not clinically apparent.

Question 4

Comedone

Answer 4

Accumulation of keratin and sebum plug that is clinically visible. Sebaceous lobule undergoes regression.

Question 5

Acne Fulminans / Pyoderma Faciale (sxs and population)

Answer 5

Most severe form of cystic acne.
Abrupt onset of deep lesions which may cause scarring. Nodules may coalesce into oozing friable plaques w/ hemorrhagic crusts.
Most common in males age 13-16.
Systemic sxs include fever, arthralgias, myalgias, lymphadenopathy, and hepatosplenomegaly.

Question 6

Acne Conglobata sxs

Answer 6

Severe eruptive acne w/o systemic sxs. Presents w/ comedones, nodules (may coalesce), abscesses, and draining sinuses.

Question 7

Acne Mechanica (cause and sxs)

Answer 7

Due to mechanical / frictional obstruction of pilosebaceous unit by things like helmets, chin straps, collars, etc. Linear and geometric distribution.

Question 8

Acne Excoriee (cause, sxs, population, tx)

Answer 8

Scratching by patient → linear lesions and post-inflammatory scarring.
Common in people w/ anxiety, OCD, or personality disorders.
Antidepressants and psychotherapy may be helpful.

Question 9

Drug-Induced Acne (onset, sxs, location, cause)

Answer 9

Onset 2-4 weeks after starting drug.
Uniform morphology, as opposed to hetergenous morphology in acne vulgaris.
Favors trunk / extremities.
Most often caused by glucocorticoids, anabolic steroids, and lithium.

Question 10

Neonatal acne (cause, prevalence, sxs, tx)

Answer 10

Due to maternal hormones.
Occurs in 20% of infants.
Superficial red papules on face.
Usually resolves w/in first 3 months of life.

Question 11

Infantile acne (timing, cause, tx)

Answer 11

Beyond 3-6 months.
Due to child hormones (not mother). Immature adrenal gland may result in elevated DHEA.
Typically resolves w/in 1-2 years. Check for endocrine tumors if it persists

Question 12

Topical acne treatments

Answer 12

Topical retinoids such as treninoin and adapalene are cornerstone for acne treatment. Unplug obstructed follicular orifice to release comedones and normalize keratin. Apply to full face.
Topical anti-inflammatories include benzoyl peroxide or topical antibiotics.

Question 13

Systemic acne treatments

Answer 13

Oral antibiotics, oral contraceptives, oral spironolactone, oral isotretinoin

Question 14

Oral antibiotics (use, general side effects, individual drugs)

Answer 14

Used for inflammatory acne that affects whole face or in people w/ acne that is not hormonally related. Best used for short time.
All 3 have risk for nausea, pseudotumor cerebri, dizziness, and teeth staining.
Tetracycline – must take on empty stomach → severe nausea. Photosensitivity. Primary oral tx for inflammatory acne.
Doxycycline – photosensitivity
Minocycline – NO photosensitivity. May cause blue/gray pigmentation on skin, lupus-like syndrome, and muscle / joint pain.

Question 15

Oral spironolactone (mechanism and use)

Answer 15

Inhibits testosterone receptor. Used for jaw line acne and hirsuitism.

Question 16

Oral contraceptive use

Answer 16

Use if acne is caused by hormones, which is common in women. Jaw line acne or hirsuitism.

Question 17

Oral isotretinoin (mechanism, use, side effects)

Answer 17

Reduces keratin plug, reduces inflammation, and reduces oil gland. Best for severe nodulocystic and scarring acne.
Does NOT cause nausea, dizziness, or teeth staining.
Side effects: Photosensitive, pseudotumor cerebri, teratogenic, hyperlipidemia, muscle / joint pain, mood changes, eczematous rash, and hepatotoxicity

Question 18

Rosacea (sxs, location, triggers, population, tx)

Answer 18

Inflammatory papules, but also fixed background redness, blushing, telengectasias. Absence of comedones (distinguishes from acne). No scarring.
Cheeks and nose are common sites.
May be triggered by sun, wind, heat, stress, hot liquids, spice foods, alcohol, or demodex mites. Always ask about blushing, acne, and ocular problems.
More common in fair-skinned individuals.
Tx w/ topical or systemic antibiotics to reduce erythema and inflammation. Laser surgery treats telangiectasias (cosmetic), but does not prevent future flares. Do NOT do laser surgery if active acne / flushing is present as it will return. Retinoids not useful as comedones are not present.

Question 19

Rhynophyma

Answer 19

Subtype of rosacea. Overgrowth of sebaceous tissue on nose w/ redness. May be permanent.

Question 20

Ocular Rosacea (sxs and prevalence)

Answer 20

Dry or gritty discomfort (foreign body sensation). Occurs in 50% of patients.

Question 21

Perioral / Periorificial Dermatitis (associated disease, hallmark, trigger)

Answer 21

Subtype of rosacea.
Orificial = eyes / nose
Spares vermillion border.
Worsens w/ topical steroids and cinnamon / mint flavorings.

Question 22

Pyoderma Faciale / Rosacea Fulminans sxs

Answer 22

Acute eruption of inflamed papules / pustules in centrofacial region.

Question 23

Where are apocrine sweat glands found?

Answer 23

Axilla, groin, skin folds

Question 24

Hidradenitis Suppurativa (cause, population, hallmark, sxs, tx)

Answer 24

Blockage of apocrine duct → rupture → chronic inflammation.
3x more common in women.
Hallmark is pain.
Recurrent nodules / boils w/ draining sinus tracts and scarring, often found in axillae.
Medical Tx: weight loss, systemic antibiotics, isotretinoin, prednisone, retinoids, and AlCl
Surgical Tx: Excision, CO2 laser ablation, or liposuction (remove glands). Use intralesion steroid injection for pain management.

Question 25

Follicular Occlusional Triad / Acne Inversa (underlying cause and 4 diseases)

Answer 25

Underlying cause involves follicular hyperkeratinization.

1) Acne conglobata
2) Dissecting cellulitis of scalp – Inflammatory nodules / papules on scalp w/ scarring. Tend to be boggy / inflamed areas. Evolve into scarring alopecia.
3) Hidradenitis suppurativa
4) Pilonidal cyst – Often found on superior gluteal cleft. Painful and scarring.

Question 26

Hyperhidrosis (sxs, types, tx)

Answer 26

Excess sweating, most often affects palms, soles, and axillae
Overproduction → maceration → bacterial / fungal growth → eccrine bromhidrosis (foul odor).
Primary – Mental / thermal stimuli w/o underlying disease. Most common.
Secondary – due to underlying disease or metabolic changes.
Tx: AlCl (plugs duct, primary tx), oral anticholinergics (systemic side effects), botox, surgical sympathectomy (divide nerve in neck plexus, used for hands, but may cause compensatory hyperhidrosis), liposuction (axillae).

Question 27

Eccrine bromhidrosis

Answer 27

Sweat leading to foul odor due to bacteria