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Saturday, December 31, 2011

Complications of Topical C.Steroid Rx

Tachyphalaxis (reduction in efficacy over time)
  • Stop using c.steroid and recommence after 7 days
Skin atrophy

Striae

Rosacea

Alteration of infection

Topical steroid allergy

Glaucoma

Disruption of HPA axis



What & How Much?

Dermatitis

Consider
  • What to prescribe?
    • Region/s affected
      • Face/Neck and flexures
        • 1% HC cream (Egocort 1%)
      • For palms and soles
        • Diprosone 
      • For other regions
        • Celestone-M
    • Lichen planus; discoid lupus; granuloma annulare
      • Diprosone OV [optimum vehicle]
  • How much to use?
    • Consider the 'finger tip' measure
      • Face and neck                    --> 2.5 units
      • Trunk front and back          --> 14 units
      • Hands and feet                   --> 1.5 units
      • Upper limb                         --> 3.5 units
      • Lower limb                         --> 5.5 units
  • How to use?
    • Apply thin layer, ideally straight after a bath or shower
    • 'Pulse therapy' helps prevent tachyphylaxis 
  • How long to use?
    • Need to balance strength of c.steroid with anticipated Rx time-horizon
      • Optimise beneficial effects
      • Avoid local side effects
      • Avoid suppression of HPA axis
    • Adult
    • Child

1 finger tip (from Wiki)
Picture supplied by DermNet NZ.




Psoriasis

Calciptriol 0.05% cream bd
  • Up to 100g per week



Compounding


Styptic Agents
  • 20% aluminium chloride
  • Monsel's solution
    • Ferric subsulfate

For psoriasis
  • Tar Cream
    • 3% salicylic acid + 3% lpc (liquor picis carbonatum)



In Case of Psoriasis

Always examine

  • Scalp
  • Joints (& associated tissue)
  • Nails


Wednesday, December 28, 2011

Tips for Procedures

Minor bleeding post-op

  • 20% aluminium chloride
  • Monsel's solution


EMLA

  • Apply to post-cryoRx to reduce pain

Dark skinned people
  • Those most likely to develop keloid

Liquid N2
  • Spray = -195.8 C
    • Dipped swab --> much less cold

UV
  • C - penetrates epidermis only
  • B - penetrates superficial dermis
  • A - penetrates deep dermis

For laser Rx
  • CO2 - resurfacing - deep
  • Erbium:YAG - resurfacing - superficial
  • Argon-pumped - telangiectasia/port wine stain
    • Or other that target oxyHb
  • Doubled Nd:YAG - pigmented lesions (epidermal)
  • For tattoos
    • doubled Nd:YAG - red tattoos
    • Q.Switched - blue/black/green tattoos

Atypical Nevi

AKA dysplastic nevi


Usually

  • >0.5cm diameter
  • Irregular border
  • Shades of pink & brown
  • Always have a macular component

Not present at birth

Prevalence 5%

Increased risk of melanoma

Several or many lesions
=> ?Atypical Nevus Syndrome
=> Accounts for 5% of melanomas in US
Consider the familial syndrome
=> >50 dysplastic nevi; FHx of melanoma, esp. 1st or 2nd degree relative
Subtle histological differences for non- versus familial

Mx for multiple dysplastic nevi should include

  • Total cutaneous survey at least every 12/12
  • Screen family members
  • Educate re self-examination
  • Excise suspicious lesions




Monday, December 26, 2011

Nevus vs. Lentigo | Melanocyte | Mole

Nevus

  • Tumor made up of nevus cells, derived from melanocytes
  • Most derived in the first 20 years of life
  • Sometimes referred to as melanocytic nevus or 'mole'
  • May or may not be pigmented


Lentigo

  • Increased pigment in basal layer
    • Melanocytes may be increased in number, but don't form nests
  • More prevalent in older age


Congenital Nevus
  • A hamartoma: a benign, but disorganized, growth of normal tissue elements in its region and which grows at a normal rate
  • Possible risk of melanoma (especially if >20cm diameter)


Melanocyte
  • Produce melanin
    • Numerous stimuli, including UV and ACTH
  • Located in the bottom layer of the epidermis
    • Also found in the CNS, bones and heart


Mole
  • As above, a common name for a (melanocytic) nevus
  • Sometimes reserved specifically as a label for an intra-epidermal nevus, many non-pigmented

Melanoma

Mimics

  • Compound nevus (with irregular border)
  • Seborrheic keratosis
  • Hemangioma
  • Dermatofibroma (pigmented)


Prognosis
  • Two most important determinants
    • Tumor thickness
    • Ulceration: present or not
  • Recurrence/survival
    • Sample sentinel lymph node
      • 1st node in lymphatic basin that drains lesion
      • Bx if depth of lesion >=1mm


Risk Factors

  • Complexion (fair skin; red or blond hair)
  • PHx
    • Atypical nevus
      • 1 lesion         --> 2* risk
      • >=10 lesions --> 12* risk
    • Melanoma
    • Non-melanoma skin cancer
    • Congenital nevus >20cm diameter




70% are superficial-spreading melanomas and slow-growing


15% are nodular melanoma and fast-growing




Any changing skin lesion (pigmented or non-pigmented)
--> must consider melanoma




Stage
  • Sample sentinel group of lymph nodes
      • # affected
      • Tumor burden within node
  • FBC; LFTs; serum LDH
  • CXR; ?CT chest?
  • ?CT or MRI brain?

Rx
  • Surgical
    • Excision margin
      • <1mm thick   --> 1cm
      • >=1mm thick --> 2cm
  • Medical
    • Interferon-alfa
      • Improves outcomes in Stage IIB - IIIC


Congenital Vascular Malformations

Congenital vascular lesions

  • hemangiomas  - 40% present @birth
    • common on face
    • mostly arterial
    • rapid neonatal growth; slow involution
  • malformations  - 99% present @birth
    • common on limbs
    • mostly venous
    • grows in proportion to child
      • result from inborn errors of vascular morphogenesis

Watch out for eroded or ulcerated skin
--> N.saline compresses; paraffin gauze; Rx infection


Consider potential for other system compromise, including psycho-social difficulties


Any extensive facial hemangioma or any midline spinal hemangioma

-->brain imaging: US scan; CT scan


Vascular malformations associated with more congenital abnormalities vs. hemangiomas


Saturday, December 17, 2011

Another Initial Approach


Hx must always consider:
  1. Timeline (acute; sub-acute; chronic)?
  2. Similar in past (new; recurrent)?
  3. Medication/drug history
  4. PHx
  5. Symptoms
    • Direct: itch or pain
    • Indirect: fever; URTI; joint pain; headache; weight loss; fatigue; malaise
  1. For examination of the lesion or rash
    • Number: single lesion; several lesions; or rash?
      • 'First impression':macro characteristics
        • Flat or raised?
          • Furthermore
            • Scaly (=> epidermis)
            • Non-scaly (=> dermis)
            • Pustular
            • Blisters
        • Skin intact or broken?
    • Distribution/region
    • Morphology
      • 'Closer inspection":
        • macular; papular; patch; plaque
        • erosion; ulcer
  2. For the Hx
    • Symptoms, as above
    • Drug Hx: prescribed; over-the-counter; recreational
    • Occupational Hx: work; hobbies/pastimes/activities/sports
    • Contacts: rash; itching; hospitalization
    • PHx:
      • .. medical: other skin disease; diabetes; auto-immune; immunosuppression; rheumatic fever
      • ...  surgical
    • FHx: eczema; psoriasis

NB:
If single lesion
--> ?is lesion or region affected prone to complications?
e.g.
SCC from venous stasis ulcer on lower leg;
Cavernous sinus thrombosis from infected 'danger zone' on the face

If rash
--> ?does it conform to a dermatomal distribution?
e.g.
Herpes zoster ('shingles')
--> ?is it symmetrical?
e.g. Acne rosacea on the face
--> ?is confined to a particular region?
e.g. Venous stasis dermatitis on lower leg
--> ?does it affect a particular cutaneous feature?
e.g. The nails in onychomycosis