Alpha hydroxy acids

shevyatiwari's version from 2015-04-20 13:13


Question Answer
Carboxylic acids or fruit acidsT
Most commonly used is tartaric acidF, lactic and glycolic
Higher MW AHA's penetrate stratum corneum poorlyT
Glycol acid is derived from milkF, derived from sugar cane. Lactic acid is derived from milk
Glycol acid is colourless, odourless, and lipophilicF - water soluble
Glycol acid is the smallest AHAT
Lactic acid is the second smallest AHAT
PHA are long carboxylic acids and are absorbed more rapidlyF, slower absorption due to size
Galactose, lactobionic acid, gluconolacctone are large AHA'sF, are PHA's
PHA's bind to more water than AHA'sT
AHA's promote degradation of corneodesmosomesT - cause detachment of keratinocytes and accelerate SC turnover
Low concentrations -> reduced melanin synthesisF, high concentrations
AHA increases the thickness of the epidermis and papillary dermisT, if 6 or 12 weeks of treatment respectively
Lower GAG, increased collagen density, disturbsement of melanin and improvement in quality of elastic fibre are all featuresF - increased GAG, all others true
May increase type 1 collagen and intercellular ground substances such as hyaluronic acidT
There can be reversal of atrophic changes from corticosteroidsT
AHA's have greater humectant and moisturising properties than PHA'sF, other way around
PHA's are more likely to be tolerated than AHA'sT
Doses of lactic acid up to 85% can cause removal of solar lentiginesT
Patients with oily skin are more reactive to glycolic acidF, less reactive
Excessive sun damage or environmental damage are sensitive to glycol acidT
It is not safe to use TCA or Jesner's solution while having glycolic peelsF - can augment results. Caution however as there can be increased peeling
Can be given with tretinoinT
Can reverse nail changesT
Useful in acne with tretinoinT
Tretinoin can -> increase depth of peel and increased exfoliationT
Pseudofolliculitis barbae can be treated with 20% glycolic acidF, 8%
Promote angiogenesisF
May prevent attachment of Demodex miteT
PHA is tolerated better than AHA in rosaceaT
Glycolic acid and lactic acid show reduced pigmentationT
AHA may inhibit tyrosinase activityT
Kligman regime refers to hydroquinone, tretinoin, topical steroidT
The closer the pH to neutral, the less irritationT
BA at room temperature is dependent o pH and concentration of AHA by the Henderson-Hasselbach equationT
Glycerin is a good vehicleF - binds strongly to AHA and reduces AHA absorption
Propylene glycol enhances penetration of AHAT
pH >3.8 results in reduced efficacyT
OTC formulations have <10% AHAT
Professional products have <10% AHAF, 30%, require sunscreen
>30% is only for physician useT
All skin types are susceptible to hyper pigmentation post peelF, hypopigmentation. Hyper pigmentation seen more in darker skinned and usually responds to tretinoin or bleaching cream
Photo protection is required for several weeks post peelT
Prophylactic acyclovir cn be used to combat HSV T
Irritant contact dermatitis it the most common adverse effectT

Recent badges