Acne Vulgaris - Dermatology - Medbullets Step 1

Snapshot

A 25-year-old woman presents to her dermatologist’s office for acne. She reports that she had severe acne when she went through puberty. However, this resolved before she graduated from high school. In the past year, as she prepared applications for medical school, she reports that she is getting acne every month around the time of her menstruation. She also reports having worse acne when her stress levels coincide with her menstruation, though this is just speculation. On physical exam, she has no active lesions, but marked post-inflammatory hyperpigmentation consistent with the resolution of previous acne lesions. She is started on oral contraceptives for management of her acne, along with a topical retinoid.

Introduction

Clinical definition
- common chronic skin condition characterized by inflammatory and non-inflammatory lesions
Epidemiology
- incidence
  - very common
- demographics
  - up to 85% of teenagers but can affect adults as well
  - more severe around puberty
- location
  - face, back, neck, chest, and upper arms
- risk factors
  - menstrual cycle
  - emotional stress
  - occlusion of skin with greasy products
  - excessive sweating
  - pregnancy
  - milk consumption
Etiology
- multifactorial
  - androgen production
  - medications
    - steroids
Pathogenesis
- blockage or outlet obstruction of pilosebaceous unit, forming comedones from
  - ↑ sebum production
  - abnormal desquamation of keratinocytes and its accumulation
  - colonization of bacteria Propionibacterium acnes
- inflammatory lesions result from
  - leakage of sebum from comedones into dermis
  - secretion of proinflammatory cells by Propionibacterium acnes
- ↑ androgen production also play a role in acne formation
Associated conditions
- polycystic ovary syndrome
- Cushing syndrome
- congenital adrenal hyperplasia
Prognosis
- in many cases, acne will resolve in adulthood
  - however, hormonal acne may persist

Presentation

Symptoms
- nodular or cystic acne may be painful
Physical exam
- inflammatory lesions
  - erythematous papules, pustules, cysts, or nodules
- non-inflammatory lesions are comedones, which are dilated hair follicles filled with keratin, sebum, and bacteria
  - open comedones are known as blackheads
  - closed comedones are known as whiteheads
- scarring
  - pitting and puckered indentation in skin

Studies

Making the diagnosis
- most cases are clinically diagnosed

Differential

Hidradenitis suppurativa
Rosacea
Folliculitis

Treatment

Management approach
- multiple factors go into the decision to treat acne, including severity of acne, type of acne, presence or potential for permanent scarring, concern for side effects, and adherence to therapy
Medical
- benzoyl peroxide
  - topical or wash
    - indication
      - for mild comedonal acne
- antibiotics
  - topical
    - indications
      - for mild non-comedonal acne
      - used in conjunction with benzoyl peroxide or topical retinoid
    - drugs
      - clindamycin
      - erythromycin
  - systemic
    - indications
      - for mild to moderate non-comedal acne
      - should not be used long-term or as monotherapy
    - drugs
      - tetracycline
      - minocycline
      - doxycycline
- retinoids
  - topical
    - indications
      - for mild to moderate acne, especially with comedones and inflammatory acne
      - often first-line when combined with an antimicrobial agent (topical or systemic)
    - drugs
      - adapalene
      - tazarotene
      - tretinoin
  - systemic
    - indications
      - for moderate to severe acne, especially cystic acne
      - for patients with existing or potential for permanent scarring
      - contraindicated in pregnancy
    - drugs
      - isotretinoin
        
        adverse effects include teratogenicity, hypertriglyceridemia, idiopathic intracranial hypertension, hepatotoxicity, cheilitis, and photosensitivity
- hormonal therapy
  - indications
    - for severe acne or acne refractory to other therapy
    - for acne that seem to correspond with menstrual cycle
  - drugs
    - oral contraceptives
    - spironolactone

Complications

Permanent acne scarring and cosmetic disfigurement

Blood, Plasma, Serum	Reference Range
ALT	8-20 U/L
Amylase, serum	25-125 U/L
AST	8-20 U/L
Bilirubin, serum (adult) Total // Direct	0.1-1.0 mg/dL // 0.0-0.3 mg/dL
Calcium, serum (Ca²⁺)	8.4-10.2 mg/dL
Cholesterol, serum	Rec: < 200 mg/dL
Cortisol, serum	0800 h: 5-23 μg/dL //1600 h: 3-15 μg/dL 2000 h: ≤ 50% of 0800 h
Creatine kinase, serum	Male: 25-90 U/L Female: 10-70 U/L
Creatinine, serum	0.6-1.2 mg/dL
Electrolytes, serum
Sodium (Na⁺)	136-145 mEq/L
Chloride (Cl^-)	95-105 mEq/L
Potassium (K⁺)	3.5-5.0 mEq/L
Bicarbonate (HCO₃^-)	22-28 mEq/L
Magnesium (Mg²⁺)	1.5-2.0 mEq/L
Estriol, total, serum (in pregnancy)
24-28 wks // 32-36 wks	30-170 ng/mL // 60-280 ng/mL
28-32 wk // 36-40 wks	40-220 ng/mL // 80-350 ng/mL
Ferritin, serum	Male: 15-200 ng/mL Female: 12-150 ng/mL
Follicle-stimulating hormone, serum/plasma	Male: 4-25 mIU/mL Female: premenopause: 4-30 mIU/mL midcycle peak: 10-90 mIU/mL postmenopause: 40-250
pH	7.35-7.45
PCO₂	33-45 mmHg
PO₂	75-105 mmHg
Glucose, serum	Fasting: 70-110 mg/dL 2-h postprandial:<120 mg/dL
Growth hormone - arginine stimulation	Fasting: <5 ng/mL Provocative stimuli: > 7ng/mL
Immunoglobulins, serum
IgA	76-390 mg/dL
IgE	0-380 IU/mL
IgG	650-1500 mg/dL
IgM	40-345 mg/dL
Iron	50-170 μg/dL
Lactate dehydrogenase, serum	45-90 U/L
Luteinizing hormone, serum/plasma	Male: 6-23 mIU/mL Female: follicular phase: 5-30 mIU/mL midcycle: 75-150 mIU/mL postmenopause 30-200 mIU/mL
Osmolality, serum	275-295 mOsmol/kd H₂O
Parathyroid hormone, serume, N-terminal	230-630 pg/mL
Phosphatase (alkaline), serum (p-NPP at 30° C)	20-70 U/L
Phosphorus (inorganic), serum	3.0-4.5 mg/dL
Prolactin, serum (hPRL)	< 20 ng/mL
Proteins, serum

Hematologic	Reference Range
Bleeding time	2-7 minutes
Erythrocyte count	Male: 4.3-5.9 million/mm³ Female: 3.5-5.5 million mm³
Erythrocyte sedimentation rate (Westergren)	Male: 0-15 mm/h Female: 0-20 mm/h
Hematocrit	Male: 41%-53% Female: 36%-46%
Hemoglobin A1c	≤ 6 %
Hemoglobin, blood	Male: 13.5-17.5 g/dL Female: 12.0-16.0 g/dL
Hemoglobin, plasma	1-4 mg/dL
Leukocyte count and differential
Leukocyte count	4,500-11,000/mm³
Segmented neutrophils	54%-62%
Bands	3%-5%
Eosinophils	1%-3%
Basophils	0%-0.75%
Lymphocytes	25%-33%
Monocytes	3%-7%
Mean corpuscular hemoglobin	25.4-34.6 pg/cell
Mean corpuscular hemoglobin concentration	31%-36% Hb/cell
Mean corpuscular volume	80-100 μm³
Partial thromboplastin time (activated)	25-40 seconds
Platelet count	150,000-400,000/mm³
Prothrombin time	11-15 seconds
Reticulocyte count	0.5%-1.5% of red cells
Thrombin time	< 2 seconds deviation from control
Volume
Plasma	Male: 25-43 mL/kg Female: 28-45 mL/kg
Red cell	Male: 20-36 mL/kg Female: 19-31 mL/kg

Cerebrospinal Fluid	Reference Range
Cell count	0-5/mm³
Chloride	118-132 mEq/L
Gamma globulin	3%-12% total proteins
Glucose	40-70 mg/dL
Pressure	70-180 mm H₂O
Proteins, total	< 40 mg/dL

Sweat	Reference Range
Chloride	0-35 mmol/L
Urine
Calcium	100-300 mg/24 h
Chloride	Varies with intake
Creatinine clearance	Male: 97-137 mL/min Female: 88-128 mL/min
Estriol, total (in pregnancy)
30 wks	6-18 mg/24 h
35 wks	9-28 mg/24 h
40 wks	13-42 mg/24 h
17-Hydroxycorticosteroids	Male: 3.0-10.0 mg/24 h Female: 2.0-8.0 mg/24 h
17-Ketosteroids, total	Male: 8-20 mg/24 h Female: 6-15 mg/24 h
Osmolality	50-1400 mOsmol/kg H₂O
Oxalate	8-40 μg/mL
Potassium	Varies with diet
Proteins, total	< 150 mg/24 h
Sodium	Varies with diet
Uric acid	Varies with diet
Body Mass Index (BMI)	Adult: 19-25 kg/m²