Sunshine and the Skin Flashcards
What happens to the skin upon chornic sun exposure?
It thickens
What is this?
How do you treat it?
Solar comedones
Usually due to chronic sun exposure and heavy smoking.
aka: Favre Racouchet syndrome - if skin has a yellow leathery texture.
Treatment:
- Extraction
- Topical retinoid.
What is this?
Solar Elastosis
Name the main 5 Idiopathic Photosensitivities
- Polymorphic light eruption
- Actinic prurigo
- Hydroa vaccinforme
- Solar urticaria
- Chronic actinic dermatitis
What blood tests should be done when a photosensitivity reaction occurs?
- Lupus Serology (ANA, ENA)
- Porphyrin analysis if relevant.
- HLA class II typping.
- Biochemistry
- Haematinics (B12, Folate, Iron)
What is the most common photosensitivity?
Polymorphic Light Eruption (PLE)
What is the treatment for PLE?
1/ Sun avoidance.
2/ Oral prednisolone. (30mg for 1 week)
What is this?
Acitinic Prurigo
Who gets Acinitic Prurigo?
90% of patients with Acinitic Prurigo have this particularly genetic serotype?
Children aged 3-10 years.
Females>Males
HLA DR4 Sublass II
What is Acitinic Prurigo related to?
What is it often confused with?
it is related to Polymorphic Light Eruption (PLE). The relationship with sun exsposure is much less clear than with Acitnic Prurigo.
It is often confused with unresponsive Eczema.
How long does Actinic Prurigo last for?
What is the treatment?
- It lasts for months as an excoriated papular and eczematous reaction on the arms, face and legs. (PLE lasts for days/weeks)
-
Treatment
- Sun avoidance and block.
- Relief: Steroids
- Prevention/Maintenance: Thalidomide.
What is this?
Hydroa Vacciniforme
How does Hydroa Vacciniforme differ from other photosensitivies?
It has distinct histological changes.
- Intraepidermal vesicle formation.
- Focal epidermal keratinocyte necrosis
What is the treatment for Hydroa Vacciniforme?
There is no proven treatment.
What are the investigations for solar urticaria?
- Porphyrins - EPP (Erythropoietic protoporphyria) and PCT (porphyria cutanea tarda) can also present similarly.
What is the treatment for solar urticaria?
- Sun avoidance
- Antihistamines
- Cyclosporin and plasmapharesis can be helpful in some cases.
What is this?
Chronic actinic dermatitis (CAD)
Who gets Chronic actinic dermatitis (CAD)?
Older (60 years plus) men
Chronically sun exposed or avid gardeners.
Describe the course of Chronic actinic dermatitis (CAD).
It gets worse over the summer months and then resolves.
It usually occurs on sun exposed areas.
Why is patch a good idea?
- Often reveals multiple contact allergens
- many to air born antigens, such as colophony (resin from pine trees and conifers) and compositae oleoresins (resin from balsam wood).
- Contact allergy to sunscreens is also common in this population.
What are the investigations for Chronic actinic dermatitis (CAD)?
- Monochromatic phototesting - (Sensitive to UVB in particular)
- Skin biopsy - helps to distinguish from mycosis fungoides or sezary syndrome (cutaneous lymphoma).
What are the treatments for Chronic actinic dermatitis (CAD)?
- Sun avoidance/ Sunblock
- Topical steroids
- Systemic therapy - either azathioprine, prednisolone, Cyclosporine, Mycofenolate mefotil.
What is this?
What are cutaneous porphyrias?
A group of inherited disorders of haem biosynthesis. They include:
- Sporadic and familial porphyria cutanea tarda (PCT)
- Hereditary erythropoietic porphyria (HEP)
- Variegate porphyria
- Erythropoietic protoporphyria.
What do the cutaneous porphyrias look like clinically?
- Painful photosensitivity
- Skin fragility
- Blistering
- Scarring
- Excess hair growth and pigmentation are also seen.
All are due to the itneraction of porphyrin with UV
How are cutaneous porphyrias diagnosed?
- Urine, blood and faecal tests looking for porphyrin.
- Also test for iron overload
- Haemochromatosis
- Liver pathology (Hepatitis, Cirrhosis and Hepatoma)
- HIV in selected patient.
How are cutaneous porphyrias treated?
- Strict sun avoidance
- Venesection (to reduce iron load) & Low dose chloroquine in porphyria cutanea tarda (PCT).
- Bone marrow transplant in selected patients.
What drugs can cause easy sunburn?
- Fluoroquinolone antibiotics
- Tetracyclines
- Chlorpromazine
- Thiazide diuretics
- Quinine
- Amiodarone
- Retinoids
What causes pain or a burning sensation of the skin?
- Amiodarone
- Chlorpromazine
What can cause solar urticaria?
Tetracyclines
What can cause skin fragility and weakness when exposed to sunlight?
- Tetracycline
- Naproxen
- Amiodarone
- Furosemide
What is xeroderma pigmentosum (XP)?
- The body becomes less able to repair skin cells after DNA damage due to a mutation in one of the enzymes responsible for repair.
- Autosomal recessive.
How do patients with xeroderma pigmentosum (XP) present?
- Present in childhood with easy sunburn.
- Early freckling
- Checkered pigmentation
- Thin and dry skin
- Frequent skin cancers.
What are some common photoaggravated conditions?
(Dermatological conditions worsened by sun exposure)
- Lupus
- Rosacea
- Dermatomyositis
- Acitinic lichen planus
- Bullous Pemphigoid and pemphigus
- Vitiligo
- Melasma
Describe the difference between organic and inorganic sunscreen?
- Organic - absorb the UV.
- UsePABA, PABA derivates, salicylates and cinnamates.
- Cosmetically acceptable.
- Can cause contact dermatitis
- Inorganic - Reflects the UV.
- Titanium, Zinc.
- Excessively white.
