Mastocytosis Flashcards
Mastocytosis
disorders of mast cell hyperplasia, can have cutaneous and/or systemic organ involvement and can have an onset of childhood or adult. 2 main types: cutaneous and systemic
Pathogenesis of Mastocytosis
KIT mutation (tryosine kinase) and CD34
Skin symptoms mastocytosis
frequently, only cutaneous: bullae, flushing, pruritus, urticaria.
Systemic symptoms mastocytosis
brain: HA, fatigue. GI cramping, N.V.D, Cardiac: chest pain, palpitations, dizzy. Bone pain.
Childhood lesions: Urticaria Pigmentosa (UP)
Tan, brown macules on the trunk. Sparaing the central face, soles and palms. 65% of all cutaneous forms. Can develop bullae, resolve between ages 3-5.
Childhood lesions: Mastocytoma
solitary, yellowish tan to brown plaque on the distal extremities. 10-35% of all cutaneous forms
Childhood lesions: Diffuse Cutaneous Mastocytosis
very rare, erythematous to yellow tan papules and plaques that become confluent Can develop bullae, resolve between ages 3-5.
Adult onset lesions
1cm reddish brown macules on trunk and proximal extremities most commonly but may appear on palms, soles and face. Can resolve w out treatment but total number of lesions will increase
Telangectasia Macularis Eruptiva Perstans (TMEP)
Rare. Macules/papules w telangiectasias and diffuse cutaneous mastocytosis. “doughy: appearance to the skin, lesions will become confluent and skin folds become thickened
Darier’s Sign
formation of a urticarial lesion when a suspected mastocytosis lesion is vigorous lly stroked. Clinical confirmation of Mastocytosis.
Classification system, indolent type
most common, cutaneous findings, very limited if any systemic findings
Classification system, smoldering type
cutaneous findings, elevated serum tryptase levels and heptosplenomegaly
Classification system, aggressive type
cutaneous findings, mast cells in bone, liver, GI, spleen. Cytopenia, leukocytosis, thrombocytopenia, very high serum tryptase. Short life expectancy
Dermatopathology for mastocytosis
“fried egg” appearance of mast cells and eosinophils. Giemsa stain is needed.
Lab testing for mastocytosis
serum tryptase levels, alpha protryptase levels, 24 hr urine for n-methyl-histamine release, plasma histamine levels. No histamine rich foods before testing: wine, yogurt, cheese, chicken liver, tomatoes, spinach
Step 1 in Dx Mastocytosis
- biopsy skin. If + mast cells –> evaluate for a KIT mutation
Step 2 in Dx Mastocytosis
assess for fever, weight loss, GI symptoms, bone pain. If GI –> endoscopy. If bone pain –> bone scan/radiographs
Step 3 in Dx Mastocytosis
Assess lymphadenopathy and hepatosplenomegaly. If + –> CT scan and liver function test. If + –> bone marrow bx
Step 4 in Dx Mastocytosis
CBC with Diff, if abnormal –> bone marrow bx
Step 5, if only positive in skin lesion bx
get baseline serum truptase level and monitor the tryptase periodically
When do lesions resolve in uritcaria v. urticaria pigmentosa
urticaria: 24 hours, UP: do not resolve
Mastocytomas can be confused with
cafe au lait macules, arthropod bites, spitz nevus, pseudolymphomas
Tx Mastocytosis
No cure, goal is to alleviate symptoms. Avoid mast cell degranulation through avoiding alcohol, anticholinergics, asa, nsaids, systemic anesthetics, heat, friction, narcotics, polymyxin b sulfate
Topicals for Mastocytosis
potent corticosteroids w occlusion, IL kenalog
Systemic tx Mastocytosis
h1 and h2 receptor antagonists (allegra + pepcid), cromolyn sodium (mast cell stabilizer) 400-800mg/day, PUVA 4x/wk, PO Prednisone. Aggressive types: interferon a2b, chemo IV cladribine
