Tony Chu

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Prevention and Management of Skin Problems
Tony Chu Dermatology at Imperial College,
Hammersmith Campus
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Skin and Renal Transplantation

• Renal transplantation demands systemic
  immunosuppression to prevent graft rejection
• Immunosuppression has a major impact on the skin
  increasing the incidence of infections,
  pre-cancerous and cancerous changes in the skin
• Many of the skin problems related to
  immunosuppression can be reduced with appropriate
  advice and management

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Immunosuppression and Infection

• Infections are more common in the
  immunosuppressed patient
• Acute bacterial - folliculitis, furunculosis,
  abscesses, cellulitis, erysipelas
• Chronic infection - tuberculosis
• Viral infections - herpes simplex, warts
• Fungal - ringworm, tinea versicolor
• Most can be treated conventionally

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Warts and the Immunosuppressed

• Warts are caused by the human papilloma virus
• They are commonest in childhood but a common
  nuisance at all times of life
• Human papilloma virus is now implicated in the
  development of cervical cancer - HPV types 16,
  18, 45 and 31
• parts of the viral DNA - E6 and E7 - link to
  specific genes in human cells, transforming them
  into cancer cells

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Immunosuppression, Warts and Skin Cancer

• Genetic model - Epidermodysplasia verruciformis
• Genetic immunosuppression predisposes to
  infection with specific wart viruses - HPV 5 and
  8
• Following sun exposure, the virus leads to
  transformation of skin cells into cancer cells
  and the development of squamous cell carcinomas

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Warts in Renal Transplant Recipients

• Warts tend to develop after 4 to 5 years
  following transplantation
• Increased in sun exposed areas
• Many will contain EV warts virus or other
  oncogenic viruses
• Real risk of these warts developing into squamous
  cell carcinomas following sun exposure

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Warts in Renal Transplant Recipients

• Management
• Regular checks with a Dermatologist
• Treatment of all warts - usually use cryotherapy
• Avoid sun exposure
• One major problem is the number of warts that
  some recipients develop - can number in the
  thousands

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Too Many Warts

• A number of our patients attend every 6 weeks and
  have gt100 warts frozen
• Painful and time consuming
• Important to target all warts as you cannot
  predict which are potentially going to develop
  into skin cancers
• Imiquimod - cream that enhances immune systems
  ability to deal with viral infections
• used successfully in RTR without effects on the
  graft

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Skin Cancer and Renal Transplant Recipients

• In the normal population, the commonest type of
  skin cancer is the basal cell carcinoma ( basal
  cell carcinoma squamous cell carcinoma is 101)
• In the renal transplant recipient, squamous cell
  carcinomas are 10X as common as basal cell
  carcinomas
• Squamous cell carcinomas are metastatic - can
  spread to other parts of the body - and this is
  increased with immunosuppression

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Skin Cancer and Renal Transplant Recipient

• Incidence of melanoma is greatly increased in the
  renal transplant recipient
• Melanoma is the most aggressive skin cancer seen
  in man
• These may arise from pre-existing moles or come
  up in normal skin
• Melanomas are often more aggressive in the
  immunosuppressed

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Skin Cancer

• The major factor in skin cancer formation is sun
  exposure
• Skin type is also important in dictating how the
  skin reacts to the sun
• Pale Celtic skin is most at risk
• Dark afrocaribean skin is least at risk

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The Sun and Man

• Effects on the skin are acute and chronic
• Acute - protective
• - Skin tanning
• - Epidermal thickening
• - Sun burn
• Chronic
• - Photocarcinogenesis
• - Photoaging

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Ultraviolet Spectrum
UVB
UVA
UVC
100-280
280-210
310-400
X rays
Visible
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UVB 280-315
UVC 100-280
UVA 315-400
Visible Light 400-700
X-ray
Stratosphere - Ozone Layer
Dead Sea Level
Sea Level
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Basal Cell Carcinomas

• Commonest skin cancer in Caucasian populations
• Major cause is sun exposure
• Common sites on face and trunk
• Not metastatic

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Squamous cell carcinoma

• Second most common skin cancer in Caucasian
  populations
• Caused by sun exposure - chronic sun exposure
• Most at risk are those with pale skin who burn in
  the sun
• Commonest on sun exposed areas
• Pre-cancerous lesion is the solar keratosis
• Metastatic potential - to regional lymph nodes,
  then liver, lungs etc

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Melanoma

• Third most common skin cancer
• Caused by severe intermittent bouts of sun
  exposure
• Found on sun exposed and non-exposed sites
• Second most common cancer to affect young women
• High metastatic potential - local, lymph nodes,
  lung, liver and brain

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Melanoma

• 30 arise in a pre-existing mole
• Features to look out for are asymmetry of the
  mole, irregular shape and irregular colour
• Most commonly arise in normal skin in renal
  transplant patients

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Methods of Preventing Long Term Skin Damage

• Avoid sun
• Avoid midday sun
• Use photo-protective clothing, hats etc
• Use sunblocks

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Avoid Sun

• Almost impossible
• Society worships the bronzed body beautiful
• Even on a cloudy day, UV will get through to the
  earths surface
• Sunlight is tricky - it will reflect off water,
  sand and other structures and can get to you even
  in the shade

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Avoid the Mid-day Sun

• Simple physics
• At mid-day the sun is directly above you and the
  amount of stratosphere it need to penetrate to
  get to you is less so more gets through
• Avoid sun exposure for an hour or two either side
  of mid-day

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UV Radiation path lengths for differing Solar
Elevations
Sun Directly Overhead
Midday
3pm
Y
Y
X
Surface
EARTH
Atmosphere
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UV Protective Clothing

• The finer the weave, the greater the protection
• Silk is best
• Nylon stockings have an SPF of about 2
• Panama hats give poor protection - holes let
  light through
• Cotton cricket hat is better

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Sunscreens

• Reflectant - reflect UVB and to a lesser
  extent UVA
• Absorbent - absorb principally UVB into
  specific chemicals and re- emit as
  insignificant quantities of heat

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Sun Protection Factor

• Indication of the amount of time it is safe to
  spend in the sun without burning
• ie an SPF of 10 would allow an exposure ten times
  greater than normal

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How can the Renal Transplant Recipient Avoid Skin
Cancer

• Proper counselling before and after
  transplantation
• Regular use of high factor sun blocks - SPF 60,
  regardless weather
• Sun protective clothing
• Avoid intense sun exposure
• Avoid the mid-day sun

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How can the Renal Transplant Recipient Avoid Skin
Cancer

• Seek advice and treatment for any warts that come
  up
• Regular screening by Dermatology Department after
  5 years post transplant
• Urgent advice about lumps that come up on the
  skin or moles that are changing

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How can the Renal Transplant Recipient Avoid Skin
Cancer

• Effect of immunosuppressant
• Azathioprine and cyclosporin seem to have the
  same effect on the skin
• Likely that tacrolimus will be the same
• Anecdotally, one patient who was developing a
  squamous cell carcinoma every 6 weeks was changed
  to mycophenolate mofetil with no detriment to his
  renal function and has been free of tumours for 6
  months