Physician Assistant Exam: Scleroderma
Scleroderma, also known as progressive systemic sclerosis (PSS), an autoimmune disease that affects the connective tissues, will be covered on the Physician Assistant Exam (PANCE). The skin is predominantly involved, although various organs, including the lungs and kidneys, can be affected as well. The skin actually becomes tight due to collagen buildup.
Scleroderma can cause pulmonary hypertension, and serial cardiac echocardiograms are often ordered to monitor pulmonary arterial pressures. Kidney function and blood pressure need to be monitored as well.
Antibodies associated with scleroderma include the anti-Scl-70 antibodies. Treatment can involve steroids and immunosuppressive medications like mycophenolate (CellCept) and methotrexate (Rheumatrex).
CREST syndrome, which has nothing to do with toothpaste, is closely related to scleroderma. CREST syndrome has five components: calcinosis, Raynaud’s phenomenon, esophageal dysmotility, sclerodactyly (a tightening of the fingers and toes rather than the whole body), and telangiectasias — that’s CREST. The treatment is multidisciplinary and can involve pharmacotherapy and surgical intervention. You see Raynaud’s phenomenon in many connective tissue diseases and autoimmune conditions.
Which one of the following antibodies is associated with scleroderma?
(A) anti-Scl-70 antibody
(B) anti-SSA antibody
(C) anti-ribonucleoprotein P antibody (anti-RNP)
(D) anti-double-stranded DNA antibody
(E) anticentromere antibody
The answer is Choice (A). Anti-Scl-70 antibodies are positive for scleroderma. Anti-RNP, Choice (C), is diagnostic for mixed connective tissue disease (MCTD), which in rheumatologic terms means “a little bit of everything.” MCTD encompasses many connective tissue diseases, and you confirm it with antibody testing. Choice (E) is positive for CREST syndrome, and Choice (B) is positive for Sjögren’s syndrome.
With antibodies and rheumatology, the questions can get funky, with all kinds of antibodies being offered as answers. For the PANCE, you should be familiar with the various rheumatologic conditions and their respective antibodies.
You’re seeing a patient diagnosed with scleroderma in the office, and you notice that his blood pressure is 146/80 mmHg. What would be your next step?
(A) Start hydrochlorothiazide (Microzide).
(B) Start lisinopril (Zestril).
(C) Start amlodipine (Norvasc).
(D) Start metoprolol (Lopressor).
(E) Start terazosin (Hytrin).
The answer is Choice (B), starting lisinopril (Zestril), which is an ACE inhibitor. This patient is experiencing scleroderma renal crisis. Significant inflammatory changes occur in the small arteries of the kidney, mediated in part by the renin-angiotensin-aldosterone system. That’s why the use of an ACE inhibitor is so important here: It can help save kidney function.
Anyone with scleroderma should have his or her blood pressure on the lower side (SBP in the 120s or 130s). Even if the kidney function gets worse, you increase the ACE inhibitor. This is the one exception to the rule that you should stop ACE inhibitors in the setting of renal failure.
The other medications aren’t bad blood pressure medications, but in the setting of scleroderma, your first choice is always going to be an ACE inhibitor. Scleroderma is big payoff test topic and an important piece of clinical knowledge; you should especially be aware of scleroderma renal crisis.
If the patient had Raynaud’s phenomenon instead of scleroderma, the answer to the example question would’ve been a calcium channel blocker, such as nifedipine. Nifedipine works well in Raynaud’s phenomenon because it’s a vasodilator and can improve blood flow to the extremities. In addition to nifedipine, the use of topical nitroglycerin ointment or paste on the affected digits is also prescribed to treat Raynaud’s phenomenon. Nitro is a potent vasodilator.