Question | Answer |
the hallmark of vasculitis | palpable purpura |
well defined raised petechiae and macules, may have a central area of hemorrhage, can become confluent, primarily on lower extremities but can extend to buttocks. can become ulcerative, necrotic in severe cases. Associated with vasculitis | palpable purpura |
cutaneous disorders associated with diabetes | acanthosis nigricans, diabetic dermaopathy, diabetic bullae, necrobiosis lipoidica, infections, lesions secondary to peripheral neuropathy, lesions secondary to peripheral vascular disease |
skin infections associated with diabetes | abscesses, furuncles, and carbuncles, cellulitis, erythrasma, candidiasis, malignant otitis externa, mucormycosis |
thickened hyperpigmented velvety plaques that develop on neck, axillae, other body folds. associated with obesity and insulin resistance | acanthosis nigricans |
Most common cutaneous manifestation of DM: | diabetic dermopathy (incidence 10-60%) |
Characterized by atrophic, small (<1 cm), brown lesions on lower extremities (2/2 microangiopathy) = | diabetic dermopathy |
appear spontaneously, usually on hands or feet, patho-unclear but they appear to be associated with peripheral neuropathy in diabetics | diabetic bullae |
three types of diabetic bullae | sterile (heals w/o scarring), hemorrhagic (heals with scarring), non-scarring (triggered by sun exposure) |
flesh colored or reddish brown papules that evolve into waxy plaques (center becomes yellow and atrophic, telangiectasis my appear, mostly seen on shins usually bilateral) | Necrobiosis Lipodica Diabeticorum |
pathophysiology of necrobiosis lipodica diabeticorum | degeneration of collegen in dermis and subutaneous fat |
treatment for necrobiosis lipodica diabeticorum | topical or intralesional steroid |
can result from neuropathic or ischemic causes from diabetes. often surrounded by callus formation, may extend through subcutaneous tissue to bone-->osteomyelitis | diabetic ulcers |
thickened hyperpigmented velvety plaques that develop on neck, axillae, other body folds; assoc w/obesity and insulin resistance | acanthosis nigricans |
appear spontaneously, usually on hands or feet, patho-unclear but they appear to be associated with peripheral neuropathy in diabetics | diabetic bullae |
three types of diabetic bullae | sterile (heals w/o scarring), hemorrhagic (heals with scarring), non-scarring (triggered by sun exposure) |
reddish brown papules, evolve into waxy plaques (center becomes yellow and atrophic, telangiectasis appear, seen on shins usually bilateral) | Necrobiosis Lipodica Diabeticorum |
2/2 neuropathic / ischemic causes from DM; often surrounded by callus formation, may extend thru subQ tissue to bone => osteomyelitis | diabetic ulcers |
uncommon benign skin disorders of papules and plaques in annular distribution, self limiting (more common in women, hands, feet, knees and elbows) usually associated with diabetes | granuloma annulare |
yellow plaques occuring near medial canthus of eyelid, upperlid>lower lid (50% associated with elevated lipid levels) | xanthelasma |
Pruritic raised erythematous plaques | Urticaria |
localized swelling of skin & mucous membranes w/pruritis; usually resolve in 24 hr, may last up to 6 weeks; | urticaria |
Urticaria triggers: | foods, drugs, infxn (viral hep, mono), stress, latex, environmental (sun, bugs) |
urticaria that extends into subcutaneous tissues | angioedema |
urticaria >6 wks duration; trigger is undetermined in 85% of cases; (poss 2/2 autoimmune or chronic dz) | chronic urticaria |
wheal is the characteristic lesion of | urticaria |
edematous papule or plaque, transient, very pruritic | wheal (urticaria) |
treatment of urticaria | Remove cause if possible; H-1 and H-2 blockers have synergistic effect, doxepin, glucocorticoids, epinephrine |
clinical evaluation of chronic urticaria | complete H&P, CBC, LFT's, TFT's, RFT's, ESR or CRP, biopsy in cases of vasculitis (referral to allergist/rheumatologist may be appropriate) |
treatment principles of chronic urticaria | avoid use of systemic corticosteroids, identify exacerbating/causative factors, around the clock use of antihistamines |
urticaria: tx: H1 blockers efficacy: | 1st gen H1 (Benadryl, hydroxyzine, Allegra, Zyrtec) better in acute urticaria; 2d gen H1 (famotidine, cimetidine)better in chronic |
urticaria/angioedema most common when | 3rd-4th decade |
necrobiosis (NLD) incidence: | 2% of diabetics; female > male |
Erythema nodosum: epi | 18-30 year olds; F>M; poss assoc w/leukemia |
Erythema nodosum: lesion | large erythematous (subQ), firm, hard nodules, LE; very painful |
Hx URI then palpable purpuric rash to buttocks, posterior thighs | HSP (Hx post Strep A infection) |