Derm Passmed Flashcards
What Drug Induced lupus?
Not all typical feature of SLE
Feature: Anti-histone antibodies + ANA +VE
Which drugs induce lupus?
Most common causes; procainamide, hydralazine
Less common causes; isoniazid, minocycline
phenytoin
Whta is shingles?
Painful dermatomal rash caused by HZV.
Presentation of shingles?
Acute,
Unilateral,
Painful blistering rash caused by reactivation of the varicella-zoster virus (VZV)
Often dormant for decades in the dorsal root ganglion nerves.
Reactivate due to several causes e.g. immunosuppression.
RF of shingles?
Increasing age >50 yo. Immunocompromised conditions Transplant patient = immunocompromised Autoimmune condition Female genre
Herpes zoster ophthalmicus
involving the eye
Herpes Zoster Oticus
infection of the ears (w/ facial paralysis)
What does psoriasis histologically demonstrate?
neutrophil infiltration into the stratum corneum.
Presentation of psoriasis?
Presents with red, scaly patches on the skin = have INCREASED risk of arthritis (psoriatic) + Cardio disease.
Worsened by lithium.
Destruction of Desmoglein 1 ?
Pemphigus Vulgaris
Destruction of Hemidesmosomes ?
Bullous Pemphigoid
What is Erysipelas ?
is bacterial infection in the superficial upper layer of the skin.
caused by s. pyogenes but can be cause by s. aureus.
1st degree burn ?
In the superficial epidermal = appear red + painful.
2nd degree ?
superficial dermal
partial thickness = appear pale pink, painful, blistering
2rd degree ?
deep dermal
partial thickness = appear white but patches of non-blanching erythema. Reduced sensation.
3rd degree ?
Full thickness = appear white / brown/ black non blistering, no pain.
Pathogenesis of burns ?
Local response with progressive tissue loss + release of inflammatory cytokines.
Reduced CO due to fluid loss + sequestration of fluid into the 3rd space (interstitial compartment)
What is Acanthosis Nigricans ?
dry, dark patches of skin that usually appear in the armpits, neck or groin.
Is AN due to an underlying condition?
Yes! Obesity T2D Polycystic ovarian syndrome Acromegaly Cushing's disease Hypothyroidism Familial Prader-Willi syndrome Drugs: oral contraceptive pill, nicotinic acid GI cancer
Pathophysiology of AN ?
Insulin resistance → hyperinsulinemia → stimulation of keratinocytes + dermal fibroblast proliferation via interaction with insulin-like growth factor receptor-1 (IGFR1).
What is Pityriasis Rosea ?
Temporary skin condition = erythematous, oval, scaly patches which follow a characteristic distribution
‘fir-tree’ appearance.
Toxic Epidermal Necrolysis ?
Life-threatening skin disorder that is most commonly seen secondary to a drug reaction.
Systemically unwell e.g. pyrexia, tachycardic + - positive Nikolsky’s sign
Steven-Johnson syndrome ?
Similar but involves less than 10% of body surfaces.
Complications of S-JS + TEN:
Volume loss
Electrolyte derangement
Hypothermia
Secondary infection
What are scabies ?
caused by mite Sarcoptes scabiei + is spread by prolonged skin contact.
It typically affects children + young adults.
Where does scabies lay its eggs?
Stratum Corneum
Can cause intense purities = assoc. w/ delayed T4 Hypersensitivity.
Treatment of choice for scabies
Permethrin 5% cream
Malathion is an insecticide lotion which is used second-line for scabies
Treatment for pyoderma ganggrenosum
Oral prednisolone
Pathophysiology pyoerma gangrenosum
Classified as a neutrophilic dermatosis
Neurophilic dermatoses are skin conditions characterised by dense infiltration of neutrophils in the affected tissue and this is often seen on biopsy
What are the 6 Ps in lichen planus
polygonal, purple, pruritic, papules, plaques, planar (flat topped)
Most common type of melanoma?
Superficial spreading melanoma
Drugs known to induce Toxic Epidermal Necrolysis ?
phenytoin sulphonamides allopurinol penicillins carbamazepine NSAIDs
What type of melanoma is common in darker skinned individuals?
Acral lentiginous melanoma
Describe Tinea Corporis?
well-demarcated, erythematous circular patch with a raised edge and central hypo-pigmentation.
