HY lecture notes:
Bone age = chronologic age = true short stature.
Bone age less than chronologic age = constitutional short stature (right-shifted growth curve) –> parents normal height, and kid will become average, but he’s just slow to start.
If USMLE doesn’t mention bone age, they might say a 14 year-old boy is still Tanner stage 2, which is akin to saying his growth curve is shifted to the right and he’ll catch up.
I’ve seen a vignette that mentions a short girl who’s Tanner stage 1 or 2 with shield chest and webbed neck, etc., and they say bone age = chronologic age. Constitutional short stature is a wrong answer to this Q. Dx clearly = Turner syndrome.
Adrenal insufficiency can cause eosinophilia. Weird detail if you’ve never heard of it before, but it means don’t go off chasing stool ova and parasites. If they tell you a guy has high K, low Na, low-ish BP, fatigue, and eosinophils of 8-15%, go with Addison, not helminth infection / stool ova and parasites.
Viral- or chemotherapy-induced aplastic anemia (usually Parvo B19, but new Q on one of the NBME forms has hepatitis A as the cause [weird]) –> all cell lines are down (low RBCs, WBC, and platelets) –> Dx with bone marrow aspiration. Sounds overkill but it’s the answer they want.
In contrast, SLE can cause pancytopenia due to anti-hematologic cell-line antibodies (i.e., antibodies against RBCs, WBCs, and platelets). SLE is frequently associated with thrombocytopenia, but if you get a vignette where all cell lines are down, the WRONG answer is “defective bone marrow production.” The correct answer is “increased peripheral destruction” (due to antibodies).
Pityriasis rosea = self-limiting viral exanthem caused by HHV6/7. Starts as Herald patch (pink ellipse) that then becomes eruption that spreads up the back and onto the shoulder blades (Christmas tree rash). This is classic, but the Herald patch and rash can start elsewhere (e.g., on the neck, etc.). Lasts 1-8 weeks, with average duration 5 weeks; itchy in 25%; most common in adults in their 20s. Can use calamine lotion to control itch.
Pediatric shingles “is a thing.” In other words, the first time people hear of this they’re 100% of the time like wtf? It can occur in peds following VZV vaccine or after true chickenpox infection. Kids with inherent NK cell problems are more susceptible.
Tx plaque psoriasis with topical vitamin D and topical high-dose steroids. Oral vitamin A, called acitretin, can also be used. Systemic psoriasis (i.e., psoriatic arthritis) can be treated with methotrexate, similar to rheumatoid arthritis. Psoriasis part of HLA-B27 phenomena –> PAIR –> Psoriasis, Ankylosing spondylitis, IBD, Reactive arthritis.
Tinea corporis (ring worm) –> Tx with topical -azole –> clotrimazole or miconazole.
Tinea capitis (cradle cap) –> Oral griseofulvin for patient only (not close contacts; this was in a family med Q where you needed to know it was patient only).
Tinea pedis –> topical terbinafine; can also use topical -azoles. But the former is better. USMLE won’t give you both to choose between; the answer on the exam will be the only antifungal listed. But I’ve seen the latter as an answer as well.
Onychomycosis (fungal nail infection) –> oral terbinafine (6 weeks for finger nails; 12 weeks for toe nails).
Candidal esophagitis (odynophagia in immunocompromised patient) –> oral fluconazole
Oropharyngeal candidiasis –> nystatin mouthwash
Biggest risk factor for candida is diabetes, NOT obesity.
Diabetes I and II are both >> risk factors than obesity.
However USMLE likes to give this Q as an morbidly obese patient with a BMI of, e.g., 67, who has a large, moist, red plaque under a breast (cutaneous candida), and then they’ll ask for the biggest risk factor –> answer = insulin resistance, not obesity. But once again, of course this could occur in a type I DM patient as well, but the answer would be something like hyperglycemia or dysglycemia, rather than insulin resistance, in a patient who is presumably of more normal BMI. Treat cutaneous candidal infections with oral fluconazole.
