2021 Case Studies – Page 2 – Derm In-Review

February 2021 Case Study

By 2021 Case Studies

February 2021 Case Study

by Jessica Kalen, MD

A 27-year-old-female with no past medical history presents for follow-up of acne. She was last seen three months ago where she was started on tretinoin cream nightly and benzoyl peroxide wash every morning. Despite use of topical medications, she reports continued flares of acne particularly around menses. On exam, she has erythematous to pink papules along the chin and jawline (Figure 1). Ultimately, she is started on spironolactone.

What is the appropriate lab monitoring for this patient?

A.) Comprehensive metabolic panel
B.) Liver function test
C.) Serum sodium
D.) Serum potassium only
E.) No lab monitoring required

Correct answer: E.) No lab monitoring required

Dermatologists frequently prescribe spironolactone to treat hormonal acne, as well as other off-label conditions. As an aldosterone antagonist, spironolactone primarily functions as a potassium sparing diuretic. However, spironolactone also has weak anti-androgenic properties and competitively inhibits androgen receptors, ultimately, halting biosynthesis of androgens.2

Spironolactone is FDA approved for management of hypertension, hypokalemia, primary hyperaldosteronism, and fluid retention resulting from cirrhosis and congestive heart failure. For dermatologic conditions, spironolactone is used as off-label therapy for hormonal acne, androgenic alopecia, hirsutism, and hidradenitis suppurativa.2 Side effects of this medication include gynecomastia, menstrual irregularities, hypotension, agranulocytosis, and hyperkalemia.

Use of spironolactone should be avoided in pregnancy due to theoretical risk of feminization of male fetuses.2 Additionally, spironolactone should be avoided in those with renal insufficiency, anuria, or Addison’s disease.2 Previously, it was thought that spironolactone should be avoided in patients with a personal history of breast, ovarian, or uterine case. However, a retrospective analysis revealed that use of spironolactone was not associated with increased risk of breast cancer recurrence in the two years following cancer treatment.3

Previously, due to perceived risk of hyperkalemia, many prescribers would monitor serum potassium levels of patients on spironolactone therapy. However, it has been shown that hyperkalemia occurs much less frequently than previously assumed.4 Thus, it has been suggested that healthy women under the age of 45 do not need routine serum potassium monitoring.5 Clinicians should consider routine serum potassium monitoring for women over the age of 45, those with cardiac or liver disease, or those taking other medications that can increase risk of hyperkalemia.5 In this clinical case, the patient is under the age of 45 with no other chronic medical conditions. Thus, the appropriate answer “no lab monitoring required.”


  1. Gold MH, et al. A cohort study using a facial cleansing brush with acne cleansing brush head and a gel cleanser in subjects with mild-to-moderate acne and acne-prone skin. Jour Drug Dermatol. November 2019;18(11):1140-1145.
  2. Wolverton SE. Comprehensive Dermatologic Drug Therapy, 4th ed. Philadelphia. Elsevier.
  3. Wei C, Bovonratwet P, Gu A, et al. Spironolactone use does not increase risk of female breast cancer recurrence: a retrospective analysis. J Am Acad Dermatol. May 2020;83(4):P1021-1027.
  4. Plovanich M, Weng QY, Mostaghimi A. Low usefulness of potassium monitoring among healthy young women taking spironolactone for acne. JAMA Dermatol. 2015;151(9):941-944.
  5. Thiede RM, et al. Hyperkalemia in women with acne exposed to oral spironolactone: a retrospective study from the RADA (Research of Adverse Drug Events and Reports) program. Int J Womens Dermatol. July 2019;5(3):155-157.

January 2021 Case Study

By 2021 Case Studies

January 2021 Case Study

by Angela Hou, MD

A 51-year-old man presents to clinic with an ongoing rash x1 month. He reports tense blisters on his trunk and lower extremities (Figure 1). He has not used any medications for these lesions. You take a perilesional biopsy for direct immunofluorescence (DIF) and a biopsy for salt split skin immunofluorescence (IMF).  DIF shows linear IgG and C3 along the dermal-epidermal junction, and the salt split skin IMF shows IgG on the blister roof.

What is the most likely diagnosis?

A.) Bullous pemphigoid
B.) Linear IgA Disease
C.) Epidermolysis bullosa acquisita
D.) Bullous systemic lupus erythematosus
E.) Pemphigus vulgaris

Correct answer: A) Bullous Permphigoid

This patient presents with a subepidermal blistering disease, which often requires direct immunofluorescence and salt split skin immunofluorescence to differentiate between the various diseases. Multiple subepidermal blistering diseases present with linear IgG and C3 along the dermal-epidermal junction, including bullous pemphigoid, lichen planus pemphigoides, epidermolysis bullosa acquisita, cicatricial pemphigoid, and bullous systemic lupus.

However, in this case, only bullous pemphigoid has both linear IgG and C3 as well as salt split skin IMF that targets the roof of the blister.

Linear IgA disease has linear IgA along the basement membrane instead of IgG and C3. Epidermolysis bullosa acquisita and bullous systemic lupus erythematosus have linear IgG and C3 deposition along the basement membrane but salt split skin IMF has IgG along the floor of the blister. Pemphigus vulgaris is intercellular IgG and C3, not along the basement membrane zone.


James, W., Elston, D., Treat, J., Rosenbach, M. and Neuhaus, I., 2020. Andrews’ Diseases of the Skin. 13th ed. Edinburg: Elsevier.