Acquired Hypermelanosis Flashcards
Melasma
Hyperpigmented brown macules on face, become more pronounced with sun exposure
Usually bilateral, symmetrical
Sites -
- Forehead
- Malar
- Upper lip
- Chin
Variable course, can be recurrent
May persist for months/years
May never fade completely (refractory)
Subtypes -
- Epidermal —> light brown, enhanced colour contrast with woods lamp
- Dermal —> grey/bluish, less colour contrast with woods lamp, less responsive to Rx esp topicals
- Mixed
Endocrine mechanism postulated, but cause unknown
Risk factors -
- Brunettes
- Ethnicity I.e. Light brown skin types, Middle East, Asia who readily tan
- Family hx
- Hormones I.e Pregnancy (esp 3rd trimester as normal physiological change, may improve spontaneously and Rx may not be necessary), Women on COCP, post menopausal women on HRT
- UV exposure
First line Rx -
- Sun protection, broad spectrum sunscreen >SPF50
- Change COCP to low oestrogen preparation, or different form of contraception
- Avoid scented cosmetic products (risk of photocontact)
- Avoid phototoxic drugs (increase sun sensitivity)
- Triple combo therapy - hydroquinone 2-4%, Tretinoin in 0.025-0.05%, hydrocortisone 0.5-1% (steroid component to reduce inflammation/irritation side effect of hydroquinone and tretinoin + inhibit melanocyte metabolism)
Second line Rx -
Chemical peels I.e. glycolic acid, salicylic acid, lactic acid + topical Rx
Azelaic acid 15-20%
Azelaic acid 20% + tretinoin 0.05%
Third line Rx - Laser IPL + topicals Dermabrasion Ascorbic acid Kojic acid + hydroquinone
Photocontact facial melanosis (Riehl melanosis)
Phototoxic reaction to skin contact with photoactive agents
Grey brown pigmentation developing rapidly over most of face
More intensive on forehead, temples
Perifollicular pigmented macules lie beyond margin
May extend to -
- Scalp
- Neck
- Chest
- Hands, forearms
Risk factors -
- Tar derivatives
- Cosmetic ingredients
- Textile materials
Ix - patch testing
Gradually improves over many months if causal substance avoided
First line Rx -
- Find the cause and avoid
- Sun protection
Second line Rx -
- Hydroquinone 2-4% + tretinoin/glycolic acid
Third line Rx -
- IPL
Poikiloderma of Civatte
Reticulate pattern Symmetrical, bilateral Sides of face, neck, upper chest after years of chronic UV exposure Sparing submental, submandibular areas Largely asymptomatic Slowly progressive Irreversible
Mottled pigmentation - Atrophy Telengiectasia Hyperpigmentation Hypopigmentation
Risk factors -
UV exposure
Phototoxic/photoallergic reactions to chemicals in fragrances/Cosmetics
Ix - Consider patch testing if allergen suspected
First line Rx -
Sun protection with high SPF sunscreen
Avoid perfumes
Second line Rx -
IPL
Erythromelanosis follicularis of the face and neck (faciei et colli)
Reddish brown discolouration, studded with pale follicular papules
Triad - hyperpigmentation, follicular plugging, erythema +/- telengiectasia
Symmetrical
Sharply demarcated from normal skin
Spreads slowly
Persistent
Not influenced by treatment
More frequent in Asians
Originally described in Japan by Kitamura
Sites - - Preauricular - Maxilla \+/- Temples \+/- lateral neck, trunk
DDx - KP and variants KP rubra Melasma Poikiloderma of Civatte Corticosteroid induced rosacea Actinic telengiectasia
Associations -
Keratosis pilaris ? Subtype
Few familial reports
Prognosis -
Generally poor response to Rx
Prone to relapse
First line Rx - Topical keratolytics - 10-20% Urea cream - 12% ammonium lactate lotion - 0.05-1% tretinoin cream
Second line Rx -
Salicylic acid peels
Glycolic acid peels
Third line -
Isotretinoin for follicular plugging
Laser treatment for erythema/hyperpigmentation
Peribuccal pigmentation of Brocq
Diffuse brownish - red pigmentation symmetrically around the mouth, sparing narrow perioral ring
May extend up central face to the forehead
+/- angles of jaw
+/- temples
Middle-aged women
DDx -
PIH post perioral dermatitis
Risk factors -
? Photodynamic substance in cosmetics
Prognosis -
Redness may fluctuate
pigmentation persistent but fades gradually if the cause I.e. cosmetics is eliminated
Ephelides (freckles) - chapter 132
Light brown pigmented macules Sun exposed skin Fair skin individuals - - Celtic (Scottish, Irish, welsh) - Red/blonde hair - Blue eyes Assoc with polymorphisms in MC1R gene AD inheritance
Skin disorders associated with freckles - Xeroderma pigmentosum Neurofibromatoses Progeria Hereditary symmetrical dyschromatoses Melanoma
Rx -
Broad spectrum sunscreen
Lentiginosis (chapter 132)
Benign pigmented macule assoc with increased number of melanocytes
SUBTYPES
Generalised lentiginosis
- Unknown pathogenesis
- No genetic factor
Unilateral (zosteriform) lentiginosis
- One side of body
- Dermatome-like vs Blaschko-linear distribution
+/- neurological abnormalities
Inherited pattern lentiginosis in Black people
- Light skinned black people, combo with red-brown hair
- AD inheritance
- Sun exposed and sun protected sites
- Spares mucosa
Eruptive lentiginosis
- Widespread occurrence very large numbers lentigines develop rapidly over months to years
- Assoc - no systemic abnormalities vs chemotherapy vs immunosuppression in transplant recipients
PUVA lentigines
Treatment exposed skin +/- nail hyperpigmentation
Dose effect —> greater number of lentigines in those who have had more Rx
Some have stellate configuration
Usually permanent
Little tendency to remit
Hypermelanosis of drug origin -
- Drug induced hyperpigmentation
- Fixed drug eruption
- Pigmentation resulting from acute photodynamic and phototoxic reactions
- Post inflammatory hypermelanosis
DRUG INDUCED HYPERPIGMENTATION
localised or generalised
FIXED DRUG ERUPTION (see drug chapter)
PIGMENTATION RESULTING FROM ACUTE PHOTODYNAMIC AND PHOTOTOXIC REACTIONS
POST INFLAMMATORY HYPERMELANOSIS
