Acne & Psoriasis

Question 1

Acne Vulgaris - Treatment

Answer 1

Cleaning and removal of oils
Mild: Topical; 6-8 weeks to show effect --> continue treatment after lesions are gone; 2X weekly for 6-12 weeks.
Tretinoin or Adapelen
Benzoyl peroxide + topical antibiotics (Clindamycin)
Azelaic acid (15% gel)
Moderate: Same as mild + PO
Tetracycline
Severe:
Isotretinoin
Other
Hormonal therapy: contraceptives

Question 2

Tretinoin/Adapelene - MoA

Answer 2

Retinoic acid. Prevents comedones and decreases inflammation

Question 3

Tretinoin - Adverse effects

Answer 3

Stinging, dryness, skin irritation, itching

Question 4

Tretinoin - Contraindication

Answer 4

Acute dermatitis

Question 5

Tretinoin - Dose

Answer 5

0,05% topical cream, apply once daily

Question 6

Benzoyl peroxide - MoA

Answer 6

Prevents comedones and decreases bacterial counts

Question 7

Benzoyl peroxide - Adverse effects

Answer 7

Dry skin, skin irritation, contact dermatitis

Question 8

Benzoyl peroxide - Interactions

Answer 8

Benzyl peroxide may decrease the conc of tretinoin

Question 9

Benzoyl peroxide - Contraindication

Answer 9

Acute dermatitis

Question 10

Benzoyl peroxide - Dose

Answer 10

5% gel, apply once daily, wash the skin after 2-12 hours depending on the irritation

Epiduo:
Benzyl peroxide 2,5% + Adapelen 0,1% Gel

Question 11

Clindamycin - MoA

Answer 11

Protein synthesis inhibitor

Question 12

Clindamycin - Adverse effects

Answer 12

Local skin irritation and burning if contact with mucosa or cracked skin.

Question 13

Clindamycin - Contraindication

Answer 13

Acute dermatitis

Question 14

Tetracycline - MoA

Answer 14

Protein synthesis inhibitor

Question 15

Tetracycline - Adverse effects

Answer 15

Discoloration of teeth and hypoplasia of enamel in pregnant women and children <8y
Nephrotoxicity
Hepatotoxicity
Photosensitivity
Vaginal/oral candidiasis

Question 16

Tetracycline - Interactions

Answer 16

Ca, Al, Fe reduced bioavailability

Aminoglycosides potentiate nephrotoxicity

Question 17

Tetracycline - contraindication

Answer 17

Pregnancy

Children <8y

Question 18

Tetracycline - Dose

Answer 18

250-500 mg bid, 1 h before or 2 h after meal.

Question 19

Clindamycin - Dose

Answer 19

10mg/mL, liniment. Apply thin later twice daily. continue treatment max 3 months.

Question 20

Isotretinoin - MoA

Answer 20

Synthetic retinoid.

Question 21

Isotretinoin - Adverse effects

Answer 21

Teratogenicity, depression, dry skin, chelitis, hypertriglyceridemia

Question 22

Isotretinoin - Interactions

Answer 22

Tetracycline –> risk for increased ICP

Question 23

Isotretinoin - Contraindication

Answer 23

Pregnancy, renal and liver failure

Question 24

Isotretinoin - Dose

Answer 24

0,5 mg/kg once daily doe 5 months PO

Question 25

Acne Rosacea - Treatment

Answer 25

Mild: Topical Metronidazole (0,75% gel) or Ivermectin (10 mg/g cream) Severe: Oral Doxycycline Very severe: Isotretinoin Cosmetic procedures: rhinophymectomy, Laser/intense pulse light Symptoms resolve after 4-6 weeks of therapy

Question 26

Metronidazole - MoA

Answer 26

Antiparasitic drug, inhibits pyruvate ferredoxin oxidoreductase

Question 27

Metronidazole - Adverse effects

Answer 27

Nausea, Vomiting, Metallic taste, Transient leukopenia, Thrombocytopenia

Question 28

Metronidazole - Interactions

Answer 28

Increases effect of warfarin | Ethanol: disulfiram-like reaction

Question 29

Metronidazole - Contraindication

Answer 29

First trimester pregnancy

Question 30

Metronidazole - Dose

Answer 30

0,75% gel. Apply thin layer 1-2 X daily for 1 month

Question 31

Doxycycline - Dose

Answer 31

40 mg PO daily for 2-3 months

Question 32

Psoriasis - Diagnosis

Answer 32

Well-marginated erythematous plaque with silvery-white surface scale. Traumatized areas --> Koebner/isomorphic phenomenon Fingernail involvement: punctate pitting, nail thickening Psoriatic arthritis --> sausage digits Auspitz sign Skin biopsy

Question 33

Psoriasis - Treatment

Answer 33

Avoid excess drying or irritation of skin, maintain adequate cutaneous hydration. Exfoliation/Peeling Localized plaque-type: Betamethasone, may combine with Calcipotriene Widespread: UV light with oral/topical psoralen (PUVA): Methotrexate

Question 34

Betamethasone - MoA

Answer 34

High potency glucocorticoid

Question 35

Betamethasone - Dose

Answer 35

1mg/mL liniment. Apply 1-2 X daily for 2-4 weeks, then max 2 X per week.

Question 36

Calcipotriene - MoA

Answer 36

Vitamin D analogue

Question 37

Calcipotriene - Adverse effects

Answer 37

Burning, itching, skin irritation

Question 38

Calcipotriene - Contraindication

Answer 38

Hypercalcemia, Vit D toxicity

Question 39

Methotrexate - MoA

Answer 39

Inhibits folate reductase

Question 40

Methotrexate - Adverse effects

Answer 40

GI, hematologic, hepatic and pulmonary reactions. Elevated liver enzymes

Question 41

Methotrexate - interactions

Answer 41

Increased effect with trimethoprim | Probenecid decreases renal excretion of methotrexate

Question 42

Methotrexate - Contraindication

Answer 42

Pregnancy

Question 43

Methotrexate - Dose

Answer 43

7,5 mg PO single dose once a week

Question 44

Acne Vulgaris- Differential Diagnosis

Answer 44

Acne Rosacea Perioral/Periocular dermatitis Folliculitis

Question 45

Acne Rosacea - Differential Diagnosis

Answer 45

Acne Vulgaris Perioral/Periocular dermatitis Malar rash of systemic lupus Seborrheic dermatitis

Question 46

Psoriasis - Differential Diagnosis

Answer 46

Eczema/dermatitis Secondary syphilis Tinae corporis