Economics of a Dermatology Practice.

Understanding the economics behind any medical practice comes down to one basic concept: Profit = Revenue - Expenses. This article aims to demystify the details that underlie this simple formula and to provide the budding dermatologist the information and the tools needed to determine their own profitability in the "real world."

Mpox virus and coinfections: An approach to rapid diagnosis.

We report a case of a 42-year-old immunocompromised (human immunodeficiency virus [HIV], CD4 count 86 cells/µL) Black male who presented with fever, oropharyngeal candidiasis, and phimosis, followed by eruption of umbilicated papulovesicles most concentrated on the face. The patient was diagnosed with Mpox (MPXV, formerly monkeypox), herpes simplex virus 1 (HSV1), varicella-zoster virus (VZV), and late latent syphilis. Tzanck smear of a Mpox lesion proved a useful and rapidly obtained pertinent negative test, lacking the typical changes of HSV/VZV (multinucleation, margination, and molding). A biopsy specimen showed viral changes consistent with both Mpox (ballooning degeneration and multinucleated keratinocytes) and herpesvirus (multinucleated epithelial giant cell within a zone of follicular necrosis). Lesion PCR was positive for HSV1 and MPXV, and negative for HSV2 and VZV. Immunohistochemistry was positive for VZV and orthopoxvirus. Empiric treatment for HSV/VZV in patients with suspected or confirmed Mpox should be considered for patients with HIV or other immunocompromised patients. It is important to recognize that MPXV, HSV, and VZV may all be present and difficult to distinguish clinically. More than one test modality (PCR, H&E, immunohistochemistry, and Tzanck) and multiple lesion samples may be required to thoroughly evaluate widespread papulovesicular eruptions, especially in immunocompromised patients.

Periorbital hypopigmentation and telangiectasias: Clues to diagnosing neonatal lupus in skin of color.

Neonatal lupus erythematosus (NLE) is an autoimmune disease characterized by a periorbital erythematous rash. Although post-inflammatory hypopigmentation and telangiectasias are known possible sequelae, these features may be particularly noticeable in skin of color. Herein, we describe two infants with skin of color in whom periorbital hypopigmentation and telangiectasias were clues to the diagnosis of NLE.

Perineal desquamation: An early sign of the Kawasaki disease phenotype of MIS-C.

Multisystem inflammatory syndrome in children (MIS-C) is a syndrome associated with coronavirus disease 2019. Various phenotypes of MIS-C have been described including Kawasaki disease (KD). Although perineal desquamation is a known early sign of KD, to our knowledge, this rash has not yet been described in the KD phenotype of MIS-C. In this article, we report two patients in whom perineal desquamation was an early clue for the KD phenotype of MIS-C.

Incidence and Outcomes of Pituitary Microadenomas in Children with Short Stature/Growth Hormone Deficiency.

BACKGROUND/AIMS: Patients with short stature (SS)/growth hormone deficiency (GHD) and precocious puberty (PP) undergo brain MRI to evaluate for structural brain abnormalities or pituitary lesions, and pituitary microadenomas are a common finding. Theoretically, a mass effect from these lesions could cause GHD and growth hormone treatment could cause them to enlarge, but they should not cause PP, at least in females. METHODS: We investigated if pituitary microadenomas cause GHD by comparing their incidence in patients with SS/GHD to that in females with PP. We performed a retrospective chart review of patients with these disorders who had a brain MRI between 2000 and 2013. RESULTS: The incidence of microadenoma was high in both groups, 18.5% for SS (n = 346) and 21.1% for PP females (n = 194), but did not differ between groups (p = 0.46). In patients with microadenomas, repeat imaging showed resolution in 58% (SS, n = 33) and 67% (PP females, n = 21). Importantly, none of the lesions grew, even in patients treated with growth hormone. CONCLUSIONS: Pituitary microadenomas are common in children with GHD/SS and PP, but it does not appear that they are a cause of GHD. They appear to be of limited clinical significance and should not be considered a contraindication to growth hormone therapy.

Thyroid Function Testing in Neonates With Maternal History of Disease.

Maternal history of thyroid disease can cause congenital hypothyroidism due to thyroid-stimulatng hormone (TSH) blocking antibodies. No guidelines exist regarding testing beyond the newborn screen. TSH and T4 levels exhibit significant fluctuations after birth which complicates testing. A total of 561 newborns with thyroid function testing done for maternal history of thyroid disease in the newborn nursery were identified retrospectively via chart review, and thyroid disease status was assessed in 352. Newborn screening data were also obtained. Of these infants, 7 had hypothyroidism with 3 having negative newborn screens. No cases of neonatal graves were identified. The 3 infants with negative newborn screens had TSH levels ranging from 6.58 to 28.4 prior to treatment with levothyroxine. All required treatment beyond age 3 years, despite trial off levothyroxine. Infants with maternal history of thyroid disease may require additional testing beyond the newborn screen. However, providers can consider delaying test until after thyroid levels are more stable.

Cutaneous skeletal hypophosphatemia syndrome (CSHS) is a multilineage somatic mosaic RASopathy.

BACKGROUND: We recently demonstrated multilineage somatic mosaicism in cutaneous skeletal hypophosphatemia syndrome (CSHS), which features epidermal or melanocytic nevi, elevated fibroblast growth factor (FGF)-23, and hypophosphatemia, finding identical RAS mutations in affected skin and bone. OBJECTIVE: We sought to: (1) provide an updated overview of CSHS; (2) review its pathobiology; (3) present a new patient with CSHS; and (4) discuss treatment modalities. METHODS: We searched PubMed for "nevus AND rickets," and "nevus AND hypophosphatemia," identifying cases of nevi with hypophosphatemic rickets or elevated serum FGF-23. For our additional patient with CSHS, we performed histopathologic and radiographic surveys of skin and skeletal lesions, respectively. Sequencing was performed for HRAS, KRAS, and NRAS to determine causative mutations. RESULTS: Our new case harbored somatic activating HRAS p.G13 R mutation in affected tissue, consistent with previous findings. Although the mechanism of FGF-23 dysregulation is unknown in CSHS, interaction between FGF and MAPK pathways may provide insight into pathobiology. Anti-FGF-23 antibody KRN-23 may be useful in managing CSHS. LIMITATIONS: Multilineage RAS mutation in CSHS was recently identified; further studies on mechanism are unavailable. CONCLUSION: Patients with nevi in association with skeletal disease should be evaluated for serum phosphate and FGF-23. Further studies investigating the role of RAS in FGF-23 regulation are needed.

Prevalence of pilomatricoma in Turner syndrome: findings from a multicenter study.

IMPORTANCE: The absence of data on the prevalence of pilomatricoma among patients with Turner syndrome served as the catalyst for this multicenter investigation. OBJECTIVES: To ascertain the prevalence of pilomatricoma among patients with Turner syndrome and to determine any association between the development of pilomatricomas and the use of exogenous hormones in patients with Turner syndrome. DESIGN: A retrospective medical record review from January 1, 2000, through January 1, 2010, was performed of all patients with Turner syndrome. Data on pilomatricomas and the use of hormone therapy were collected. SETTING: University of California-Davis Medical Center, University of Nebraska Medical Center, and The University of North Carolina at Chapel Hill. PARTICIPANTS: Patients with a diagnosis of Turner syndrome. MAIN OUTCOME MEASURES: Prevalence of concomitant pilomatricoma and diagnosis of Turner syndrome. Secondary outcome measures included the use of the exogenous hormones estrogen or recombinant human growth hormone (rhGH). RESULTS: In total, 311 patients with Turner syndrome were identified from these 3 institutions. Among them, 8 patients (2.6%) were diagnosed as having pilomatricomas. Before the development of pilomatricomas, 5 patients had been treated with rhGH but not estrogen, 1 patient had received estrogen but not rhGH, and 2 patients did not receive either therapy. CONCLUSIONS AND RELEVANCE: Although the prevalence of pilomatricoma among the general population is unknown, this study demonstrates a high prevalence (2.6%) of pilomatricomas among patients with Turner syndrome. No apparent relationship was noted among our patients or in the literature between the use of rhGH and the development of pilomatricomas.