Chapter 37 - Acne Vulgaris Flashcards
Are P. acnes organisms Gram positive or negative? Motile or non-motile?
- Gram positive
- Non-motile
What are the three species of Propionibacterium?
- P. acnes, P. granulosum, and P. parvum (rare)
- All three can contribute to acne
What causes P. acnes to fluoresce under Wood’s light?
They produce porphyrins, primarily coproporphyrin III
If dihydrotestosterone stimulates sebum production, does estrogen decrease sebum production?
Yes; however, the dose of estrogen required to suppress sebum production is greater than the dose required to suppress ovulation, thus oral contraceptive pills may help with acne, but higher doses are required to clinically reduce sebum production
What is the name for the most severe form of cystic acne?
Acne fulminans
What does SAPHO stand for?
Synovitis, Acne, Pustulosis, Hyperostosis, and Osteitis
When osteolytic bone lesions occur in the context of acne fulminates, which joints are most commonly affected?
The clavicles and sternum
Which entities comprise the follicular occlusion tetrad?
Acne conglobata, dissecting cellulitis of the scalp, hidradenitis suppurativa, and pilonidal cysts
What are the 3 bacteria involved in acne?
1) Propionibacterium acnes, 2) P. granulosum, 3) P. parvum. They fluoresce under Wood’s lamp due to porphyrins (coproporphyrin III)
Where are androgen receptors located in the skin?
Basal layer of sebaceous glands, ORS of hair follicles
What is the black color in open comedones due to?
Melanin deposition and lipid oxidation of packed keratin
What is the difference between acne fulminans and acne conglobata?
Both have nodulocystic acne. Acne fulminans have systemic symptoms whereas acne conglobata does not
What is the follicular occlusion tetrad?
1) Acne conglobata, 2) dissecting cellulitis, 3) HS, 4) pilonidal cysts
What is the gene mutation in PAPA syndrome?
PSTPIP1, proline serine threonin phosphatase interacting protein 1, aka CD2 Ag-binding protein 1
What is the treatment for solid facial edema?
Isotretinoin 0.2-0.5 mg/kg/d +/- ketotifen 1-2 mg/d x 4-5mths
What is “fiddler’s neck” (ie. well defined lichenified hyperpigmented plaques with comedones) an example of?
Acne mechanica
What psychiatric disorders are at higher risk of acne excoriee des jeunes filles?
Anxiety, OCD, personality disorders
What are some drugs that can cause drug induced acne?
Anabolic steroids, corticosteroids, corticotropin, phenytoin, lithium, isoniazid, iodies, bromides and EGFR inhibitors
What are some agents that can cause occupational acne?
Cutting oils, petroleum based products, chlorinated aromatic hydrocarbons, coal tar derivatives
What % of healthy newborns are affected by neonatal acne?
20%
How is infantile acne different from neonatal acne?
Presents at 3-6mths old (vs. 2wks old), more prominent comedones, may lead to pitted scars
What does HAIR-AN syndrome stand for?
Hyperandrogenism, insulin resistance, acanthosis nigricans. These patients have an increased risk of CVD, DM
What are some examples of systemic treatment options for acne? Note: broad categories
Antiobiotics, OCP, diuretic/spironolactone
Which OCPs are FDA approved in the treatment against acne?
Yaz, Ortho Tri-Cyclen, Estrostep
What initial bloodwork is needed before starting a patient on PO isotretinoin?
TGL, cholesterol, LFTs, CBC, ESR, pregnancy test
What are the factors that increase risk of developing acne?
- XYY chromosomal genotype
- PCOS
- Hyperandregenism
- Hypercortisolism
- Precocious puberty
What porphyrin does P. acnes primarily produce?
Coproporphyrin III
In respect to acne, where are the androgen receptors located?
- Cells of basal layer of sebaceous glands
2. Outer root sheath of hair follicle
Where are the androgens produced?
- Gonads
- Adrenal gland
- Sebaceous glands
What is the DDx for acne eruption in an oncology patient?
- Steroid induced acne
- Neutrophilic eccrine hidradenitis
- Folliculodystrophy of immunosupression
- Other folliculitis
What topical retinoid is photo-stable?
Adapalene
Which systemic tetracycline has the least resistance to P. acnes?
Minocycline
What is the half life of isotretinoin?
18 hours
