38 results
Tinea Versicolor (Pityriasis versicolor) 
NOT a dermatophyte infection 
Caused by saprophytic, lipid-dependent yeasts 
Clinical 
 •
Potassium hydroxide (KOH
Erythema Annulare Centrifugum (EAC),
This is erythema annulare centrifugum (EAC), one of the “figurate erythemas.” These lesions
KOH will be negative
Disseminated Blastomycosis - Computed tomography (CT) of his chest showed an infiltrate in the right upper
Blastomycosis #CT #KOH
Blastomycosis Summary

Pathogen: 
 • Dimorphic fungus - Blastomyces dermatitidis or Blastomyces gilchristii.
 • The fungus lives
1) Fresh wet (KOH
Calcium homeostasis is a process controlled by chiefly by hormones vitamin D and PTH. 
Vitamin D
active form, 1,25(OH ... Both 25(OH)D and ... 1,25(OH)2D are
Mechanism of malignancy-associated hypercalcemia. Abbreviations: 1,25(OH)2D, 1,25-dihydroxyvitamin D; NHL, non-Hodgkin lymphoma; PTH, parathyroid hormone; PTHrP, PTH-related
Abbreviations: 1,25(OH
Hypercalcemia Evaluation
1) Clinical clues
 - Is the patient symptomatic?
 - Family history?
 - Have you done
PTHrp • 25 OH ... VitD & 1,25 OH
Hypocalcemia - Differential Diagnosis Algorithm - Low and High PTH
LOW PTH - Hypoparathyroid
 - Congenital (Pediatric)
HIGH PTH - 25-OH ... anti-convulsants) - 25-OH
Steroid Synthesis Pathway

(OH, hydroxy; HSD, hydroxysteroid dehydrogenase; DHEA, dehydroepiandrosterone; pink, common enzymes affecting CAH, purple –
Synthesis Pathway (OH
Hypercalcemia - Differential Diagnosis Algorithm
Primary Hyperparathyroidism
 • Adenoma
 • Hyperplasia
 • MEN 1 and 2A
Tertiary Hyperparathyroidism
Conversion of 25-OH ... D3 to 1,25-(OH)