19. Pediatric Rheumatology Flashcards
Review of lab tests: ANA: what does a higher titer indicate according to this guy?
What result on ANA would prompt you to get an ENA?
Higher the ANA titer, the more likely to be significant later on. Generally under 160 is negative.
ANA also indicates a pattern: nuclear, peripheral, centromeres, etc.
A homogeneous or speckled pattern of ANA + suspicion of autoimmune dz should prompt an ENA.
What is tested for with an ENA panel?
(this is what you order if you have a high ANA with homogenous/speckped pattern + suspicion of autoimmune dz).
Subset of ANA antigens. Classic ones are:
Anti-Smith –> specific for Lupus
SSA and SSB (aka anti-Ro and anti-La) –> sjogren’s
(Big picture for auto-immune diseases of childhood)
What are the most common autoimmune dz’s in each category
Vascular?
Cutaneous?
Vasculitis?
Any dz of these types that we see in adults, we also see in children.
Vascular: Raynaud’s, Chilblains (pernio)
Cutaneous: Limited Scleroderma (morphea)
Vasculitis: Henloch-Schonlein Purpura, Kawasaki’s
ALSO, Dermatomyositis
**per lecturer, focus on Raynaud’s and Morphea
Raynaud’s: how would we describe the dz?
What needs to be present clinically to dx it?
Exaggerated response of blood vessels to thermoregulation.
Need to have at least 2 color changes to dx Raynaud’s. Usually white to blue, but often then goes from blue to red.
What is the difference between Raynaud’s and Chilblain’s?
Raynaud’s = vasospasm of arterioles
Chilblain’s (aka pernio) = Dilation of venules
Raynaud’s: what is the distribution of the skin changes?
Usually induced by what?
What 2 forms are there?
Reversible digital skin color changes that are well-demarcated.
Cold-induced (or due to stress, vibration)
Types: Primary (Raynaud’s dz) and Secondary (Raynaud’s syndrome)
Some causes of secondary Raynaud’s?
In kids: -Connective Tissue diseases (scleroderma, lupus, MCTD, sjogren’s, dermatomyositis)
-Stimulants (ADD meds: amphetamine, methylphenidate)
In adults: Occlusive Arteriole dz, vascular injury like frostbite, Drugs/Toxins, Hyperviscosity and Paraproteins (ok, sure, whatever)
What is happening to cause the progression from white to blue to red in Raynaud’s?
How can you determine clinically if the problem is due to small vessels, or medium ones?
See pic: Fingers initially white due to lack of blood flow, then blud as vessels dilate to keep blood in tissues (and blood loses oxygen to tissues), finally red as blood flow returns
Can test for medium-vessel issues by compressing both radial and ulnar arteries simultaneously, and seeing how long blood flow takes to return via palmar arterial arches. Normal return = 6 secs.
What is this pic of? How is this relevant to Raynaud’s?
Pathologic Nailfold Capillaries. Present in dermatomyositis.
Relevant because good indication of whether Raynaud’s is primary or secondary.
A high ANA titer (> 160) –> secondary
Pathologic Nailfold Capillaries –> secondary
We’ve seen this pic about 100 times. What disease states can we suspect based on the upper right pic, and the two lower pics?
Upper left is normal
Upper right is scleroderma. Note dilatation, inflammation of caps.
Two lower are dermatomyositis. Note inflammation, drop-outs. Risk for developing connective tissue disease.
What is this pic? Notable?
Chillblains. aka perniosis.
Note mottled purple discoloration. Due to venule vasodilation, and subsequent pooling of blood in veins.
What is this?
Associated with what environments?
Describe the characteristics of the lesions?
What would we see on histo?
Chillblains.
Associated with wet/cold conditions
“Skin lesions: pruritic or painful, erythematous or violaceous plaques, papules or nodules that develop on the fingers and toes after prolonged exposure to a cold, damp environment. The histopathology consists of a superficial and deep angiocentric lymphocytic infiltrate with papillary dermal edema.”
On histo: will see inflammation, edema
What are the two things this could be? How would you distinguish them?
Could be Lupus, could be Chilblains (vasculitis) that is ulcerating. (usually don’t see this in Raynaud’s - note there is some desquamation here)
Hard to distinguish without a biopsy. If Lupus: neutrophilic inflammation in arterioles. If Chilblains, lymphocytic infiltration in venules.
What is this, where would we see it?
Harmful?
Acrocyanosis. Normal redistribution of bloodflow after birth and during early infancy. (shunting blood from periphery to core)
Will see in NICU. Not harmful, usually self-corrects in a few months.
Scleroderma: What are the three types?
Which ones do we see in children?
(Autoimmune disease)
Divided into Localized (skin only) & Systemic: Limited or Diffuse
(3 types: Localized, Limited Systemic, Diffuse Systemic)
ONLY see Localized in kids. –> only see skin findings of scleroderma in kids.
Localized Scleroderma: what is the most common subtype?
Generally, what does it cause?
Morphea.
This is what we see in kids.
Localized fibrosis limited to dermis, subdermis and superficial muscle.
Localized Scleroderma/Morphea: are there lab findings? systemic symptoms?
Where might the lesions occur?
At what point do we treat this?
Morphea: NO lab findings, NO systemic sx (remember this is Localized as opposed to Systemic Scleroderma)
Lesions occur on face, trunk or extremities, singly or in multiples.
Lesions may regress spontaneously. If the lesions cross joints or are on face, we treat aggressively.
In some cases may be called Linear (subtype of Morphea)
What is this?
Why is there hypopigmentation?
Morphea.
Formerly these were hard/inflammatory areas. Then the melanocytes were killed yielding post-inflammatory hypopigmentation. Referred to as “burn-out”
Histo of Morphea: On this pic, what is normal? what is abnormal?
Normal epidermis.
Normal upper reticular epidermis.
Thick/crowded collagen bundles.
Purple: nodules of lymphocytes and plasma cells.
Thickened fibrous septum at bottom of pic, (deep in dermis).
What is this? would we treat? why?
Morphea/Linear Scleroderma
Treat aggressively because it crosses the knee joint. May tighten –> cause contracture.
What is this?
Morphea on posterior thorax.
What is this? What is one complication?
Linear scleroderma to the face (type of morphea).
“Coup de Sabre” (blow of the sword)
worst type of linear scleroderma, rare
complications: obvious disfiguration, can cause decreased oral aperture.
What is this? what is seen on imaging?
Linear scleroderma/morphea (coup de sabre)
facial hemiatrophy
On imaging, see that it goes right through the dermis and into calvarium
What is this?
Linear scleroderma of the hand.
