The Skin and Ultraviolet Light tutorial

Question 1

What is the function of vitamin D ?

Answer 1

Its major role is to increase the flow of calcium into the bloodstream, by promoting absorption of calcium and phosphorus from food in the intestines, and reabsorption of calcium in the kidneys, thus enabling normal mineralization of bone.

Question 2

What does vitamin D deficiency result in, in kids ?

Answer 2

Results in rickets - a bone disease characterised by softening and weakening of the bones due to loss of calcium and phosphate from the bones, which eventually causes destruction of the supportive matrix

Question 3

What does vitamin D deficiency result in, in adults ?

Answer 3

Osteomalacia

Muscular weakness, bone pain and bone fractures. Initially symptoms of muscle weakness and bone pain may be subtle and go undetected.

Question 4

What can long-term uncorrected vitamin D deficiency result in ?

Answer 4

Osteoporosis

Question 5

What are some of the associated risk of vit D deficiency ?

Answer 5

associated increased risk of common cancers, infectious diseases, autoimmune diseases and cardiovascular disease

Question 6

What is the recommendations for sun light exposure and why ?

Answer 6

Recommended that you get 15-20 mins per day this is because vit D deficiency can increase the risk of skin cancer hence helping to meet your requirements of vit D

Question 7

History:

• A child aged 16 months presents in March 2009. He has developed gradual bowing of legs since moving to Dundee from Nigeria a few months ago with his parents and older sister.
• He is breast fed daily and also has a little cow’s milk and yoghurt in his diet.

Examination:

• Normal apart from mild bilateral leg bowing.

1. What is the diagnosis?
2. What are the contributing factors?
3. How could the diagnosis be confirmed?
4. Suggest a treatment

Answer 7

1. What is the diagnosis? - rickets
2. What are the contributing factors? - Lack UV - Winter in Dundee, dark skin type, Diet - Breast fed from deficient mother, limited other sources Vit D
3. How could the diagnosis be confirmed? - Measure serum Vitamin D
4. 6. Suggest a treatment - Vit D supplements

Question 8

Describe the sequence of events leading to the development of non-melanoma skin cancer

Answer 8

1. Epidermal keratinocyte DNA damaged by solar UV radiation
2. Mutation of tumour suppressor genes and loss of apoptotic function
3. Mutation of protooncogenes
4. Clonal selection of non-apoptosing, mutated cells
5. Solar UV suppresses normal cell mediated immune response against tumour cells
6. Further growth to macroscopic tumour

Question 9

• A 68 year old retired bank worker and keen golfer, who had a successful renal transplantation 12 years ago, presents to the Dermatology Clinic with asymptomatic, erythematous and hyperkeratotic lesions on his face and back of hands.
• His current medications are prednisolone, cyclosporin and azathioprine (to prevent rejection following renal transplant).
• The lesions are diagnosed as actinic keratoses and treated with liquid nitrogen cryotherapy.

Q1: Record the risk factors for skin cancer present in this case:

Answer 9

1. Age, outdoor hobby, immunosuppression, skin type, actinic keratoses

Question 10

• A 76 year old retired gardener and keen fisherman presents with an ulcerated lesion of his upper nose. He is otherwise well and on no medication. He spent time in Asia when he was in the navy in his youth and remembers being sunburnt.
• The lesion is excised and histology confirms basal cell carcinoma.

Q2: What advice would you give regarding future risk of developing skin cancer?

Q3: What advice would you give this patient to reduce risk of further skin cancer in the future?

Answer 10

Q2: What advice would you give regarding future risk of developing skin cancer? - Increased risk now

Q3: What advice would you give this patient to reduce risk of further skin cancer in the future? - Hat, sunscreen, avoid sun exposure especially in middle of the day