Systemic disease Flashcards
What is acanthosis nigricans?
Velvety, thickened hyperpigmented, papillomatous, “dirty”-looking skin affecting axilla, groin and neck often with multiple skin tags.
associated with insulin resistance and the metabolic syndrome (obesity, type II diabetes or other endocrinopathies, whether congenital or acquired).
malignancy (usually GI especially gastric carcinoma) is suspected if the onset is abrupt and findings are severe, especially if mucous membranes or palmar skin is involved (tripe palms)
What is pyoderma gangrenosum?
Associated with UC, inflammatory arthritis, Crohn’s, diverticulitis, chronic hepatitis, Behcets disease
Leukaemia/myeloma
Ulceration on the leg
Topical and oral steroids may be effective as may ciclosporin, but recurrence on stopping treatment is quite common
What are the cutaneous findings associated with diabetes?
necrobiosis lipoidica, usually affecting pretibial skin rubeosis (chronic flushed face) diabetic dermopathy (atrophic hyperpigmented lesions on lower legs -- an under-diagnosed entity probably present to some degree in 50% diabetics; male > female) generalised granuloma annulare vitiligo acanthosis nigricans lipodystrophy vascular changes xanthomata (eruptive in uncontrolled diabetes) yellow skin (increased serum carotene) dry and wet gangrene candidiasis necrotising fasciitis foot ulcers
What is necrobiosis lipoidica?
Skin condition characterised by circumscribed, multicoloured, waxy, atrophic plaques. There are usually between one and three lesions present. Sometimes a history of preceding trauma.
affect skin over bony areas
Long-standing plaques may ulcerate and slowly heal with depressed scars
More common in females an ddiabetics
What is dermatitis herpetiformis?
chronic, recurrent, intensely pruritic eruption occuring symmetrically on the extensor surfaces of the extremities and trunk.
Typically groups of vesicles are seen but these are usually excoriated.
diagnosis is confirmed with a skin biopsy with immunofluorescence.
Jejunal biopsy reveals abnormal mucosa in the majority of patients.
Treated with dapsone (reactions of haemolysis and agranulocytosis)
What are the differentials for systemic causes of pruritus?
Metabolic/endocrine: hyper- and hypothyroidism, chronic renal failure, carcinoid
Malignancy: lymphoma, leukaemia, myeloma, solid cancer (rare)
Drugs: aspirin, alcohol, morphine, codeine
Haematological disease: polycythaemia rubra vera, iron deficiency
Hepatic disease: obstructive biliary disease, cholestasis of pregnancy
Pregnancy (without cholestasis)
Xerosis: dry skin alone is sometimes responsible for pruritus
What are the tests for severe pruritus or ones that don’t respond to treatment?
CXR Stool culture (hookworm) Fasting blood glucose Referral for pelvic exam and smear Treat with oral antihistamines like cetirizine or hydroxyzine
What is erythema multiforme?
reaction pattern of blood vessels in the skin with secondary epidermal changes which classically are red and like a bull’s eye hence the term ‘target lesions’.
They can be macular but are often elevated with vesicle or bulla formation centrally.
The extremities are typically affected and mucous membranes are also often involved.
The age of onset is under 20 years in 50% of patients.
Caused by HSV, penicillin, sulphonamides, phenytoin and allopurinol
Fever, weakness and malaise
True lesions of EM have 3 colours in them
What is erythema noduosum?
immunological/ inflammatory reaction pattern of the subcutaneous fat characterised by the appearance of tender, erythematous, bruise-like nodules usually on the lower legs.
Associated symptoms of fever, malaise and arthralgia are common.
Younger adults aged 15-30 years tend to be affected. It occurs in females three times more often than males
Triggered by infection (strep, TB), sulphonamides, oral contraceptives, sarcoid, behcet’s disease, IBD
Treatment: Rest, NSAIDs, prednisolone, usually resolves in 6 weeks
What is acquired ichthyosis?
non-hereditary skin condition that is characterised by dry skin with scaling that is often described as ‘fish scale skin’. It usually appears in adult hood
Caused by Hodgkin’s disease and allopurinol
Diagnosed clinically and with skin biopsy
treatment involves using emollients and to prevent infections. It can also improve if the underlying disease is treated or the drug is stopped.
What is dermatomyositis?
rare acquired muscle disease that is accompanied by a rash
Factors such as genetic predisposition, autoimmune or drugs can play a part. It can also represent an underlying malignancy
Linked to an increased likelihood of developing cancer, particularly of the cervix, lungs, pancreas, breasts, ovaries and gastrointestinal tract
rash can either be symptomless or itchy or burning. It is reddish or bluish-purple patches affecting the sun exposed areas. A violaceous rash may also affect the cheeks, nose, shoulders, upper chest and elbows.
Helitrope rash: purple eyelids
Gottron papules: Purple papules or plaques found on bony prominences especially the knuckles.
What is the treatment for dermatomyositis?
Prednisolone
Control skin and muscle disease
Resolves in 1/5 patients
What are the common drugs which cause rashes?
Penicillins/ sulphonamides Anticonvulsants NSAIDS Thiazide diuretics Allopurinol Gold and penicillamine
What is toxic erythema?
7-10 days after introduction of the drug (or 1-3 days after reintroduction)
Fever, malaise, pruritus
Most often morbilliform (symmetrical erythematous macules and papules ), however the rash can be scantiform (ting red papules) or confluent forming large erythematous patches or urticated plaques
Can progress to erythroderma or toxic epidermal necrolysis
Should subside in a week
What is Steven Johnson Syndrome?
type IV hypersensitivity reaction that typically involves the skin and the mucous membranes.
Prodrome of fever and respiratory symptoms
Red macules
Central blister formation
Epidermal necrosis
Extensive oral involvement
Involves two mucosa sites
Severe eye involvement
Prolonged course
Caused by mycoplasma, HSV, NSAIDs, sulphonamides, penicillins, anticonvulsants, allopurinol
