Derm the skin in systemic disease Flashcards
What can effective dermatological diagnosis help with?
- preventing/reducing internal organ damage via early diagnosis
- detection of internal malignancy
example of disease where skin is just one of many targetted organs
sarcoidosis
example of disease where skin is a sign of internal disorder
flushing in carcinoid syndrome
example of disease where skin condition is telltale sign of underlying condition
pyoderma gangrenosum in IBD
example of disease where skin leads to 2ndary organ involvement
high output cardiac failure in erythroderma
things for dermatomyositis investigation
- anti-nuclear antibody (positive)
- creatine kinase (look at muscle activity)
- Skin biopsy
- LFT
- electromyography
- Screening for internal malignancy
What is the criteria for drug reaction with eosinophilia and systemic symptoms (DRESS)?
Fever ≥ 38.5°C
Lymphadenopathy ⩾ 2 sites, > 1cm
Circulating atypical lymphocytes
Peripheral hypereosinophilia >0.7 × 10^9
Internal organs involved - (liver, kidneys, cardiac)
Negative ANA, Hepatitis / mycoplasma, chlamydia
Skin involvement
- >50% BSA
- Cutaneous eruption suggestive of DRESS e.g. facial oedema
- Biopsy suggestive of DRESS
what organs are commonly affected in DRESS?
- Liver (hepatitis)- most frequent cause of death
- Kidneys (interstitial nephritis)
- Heart (myocarditis)
- Brain
- Thyroid (thyroiditis)
- Lungs (interstitial pneumonitis)
how to treat DRESS
- WITHDRAWAL OF CAUSATIVE AGENT
- corticosteroids are 1st line treatment: may require for months
- mortality is 5-10%
What is graft versus host disease?
Multiple-organ disease
Affects ~10-80% of allogenic haematopoetic stem cell transplants (HSCT)
Pathogenesis: donor-derived T-lymphocyte activity against antigens in an immunocompromised recipient
how is sarcoidosis diagnosed?
highly variable presentation = diagnosis of exclusion. Investigations required for diagnosis and to investigate extracutaneous involvement
What is scurvy and what are key symptoms?
Vitamin C (ascorbic acid) deficiency
- Spongy gingivae (gums) with bleeding and erosion
- Petechiae, ecchymoses, follicular hyperkeratosis
- Corkscrew hairs with perifollicular haemorrhage
What do we call protein deficiency and what are key features?
kwashiorkor Systemic features: - Hepatomegaly - Bacterial / fungal infections - Diarrhoea - Loss of muscle mass - Oedema - Failure to thrive Skin signs: - Superficial desquamation (large areas of erosion) - Sparse, dry hair - Soft, thin nails - Cheilitis (lip inflammation)
What are symptoms of vitamin B3 deficiency (niacin)?
Deficiency:
- Dermatitis | Diarrhoea | Dementia | Death
Cutaneous manifestations:
- Photodistributed erythema
- ‘Casal’s necklace’
- Painful fissures of the palms and soles
- Peri-anal, genital and perioral inflammation and erosions
What is carcinoid syndrome and what are symptoms?
Signifies metastases of a malignant carcinoid tumour Due to 5-HT secretion Flushing in 25% of cases Other symptoms: - Diarrhoea - Bronchospasm - Hypotension
What is Stevens-Johnson Syndrome / Toxic Epidermal Necrolysis and what are symptoms?
Derm emergency! (Rare)
Prodromal: flu-like symptoms
Abrupt onset of lesions on trunk > face/limbs
Macules, blisters, erythema – atypical targetoid
Blisters merge – sheets of skin detachment ‘like wet wallpaper’
Extensive full thickness mucocutaneous (epidermal) necrosis <2-3 days
Where does the name Stevens-Johnson Syndrome / Toxic Epidermal Necrolysis come from?
There is a spectrum:
SJS IF:
BSA detachment <10%
Mortality = 10%
SJS/TEN
BSA detachment 10-30%
TEN
BSA detachment >30%
Mortality >30%
What causes Stevens-Johnson Syndrome / Toxic Epidermal Necrolysis?
Cell-mediated cytotoxic reaction against epidermal cells
Drugs cause >80% of cases
May be started up to 3 weeks prior to onset of rash
What drugs can cause Stevens-Johnson Syndrome / Toxic Epidermal Necrolysis? (9)
Antibiotics Beta-lactams Sulphonamides Allopurinol Anti-Epileptic Drugs Phenytoin Carbamazepine Lamotrigine NSAIDs
How can we assess the severity of Stevens-Johnson Syndrome / Toxic Epidermal Necrolysis?
SCORTEN Criteria: age >40 HR >120 initial % epidermal detachment serum urea + glucose + bicarbonate presence of malignancy
What are complications of Stevens-Johnson Syndrome / Toxic Epidermal Necrolysis?
Death - Overall mortality 30%
Blindness, dehydration, hypothermia/hyperthermia, renal tubular necrosis, eroded GI tract, interstitial pneumonitis, neutropaenia, liver and heart failure
What is zinc important for?
Important role in 200 enzymes – regulation of lipid, protein, nucleic acid synthesis
Roles in wound healing, antioxidant
What are causes and symptoms of zinc deficiency?
Deficiency: genetic (SLC39A4) or acquired
- Triad of Dermatitis | Diarrhoea | Depression
Perioral, acral and perineal skin in particular is affected with scaly erosive erythema
cutaneous manifestation of niacin (vit B3) deficiency
- photodistributed erythema
- casal necklace
- panful fissures of the palms and soles
- chellitis and glossitis
- vaginitis with erosions
New onset of itching without a rash may be a manifestation of an underlying cancer - true/false
true
What illness presents as Flu-like illness, sore eyes and oral ulceration.
- Followed by extensive painful rash
What disease is this?
Stevens-Johnson Syndrome / Toxic Epidermal Necrolysis
Treatment for Stevens-Johnson Syndrome / Toxic Epidermal Necrolysis
1st line: withdrawal of causative agent and urgent evaluation (SCORTEN)
