What is the diagnosis and treatment for a 49-year-old male patient presenting with subcutaneous masses, likely scar tissue, following poor hygiene during shaving, with a request for an ultrasound of the neck and prescription for selenium sulfide (an antifungal and antibacterial medication)?

From the Guidelines

I strongly recommend against proceeding with the ultrasound of the neck as initially planned, and instead, consider a more targeted approach based on the patient's risk factors and symptoms, as suggested by the clinical practice guideline for evaluation of the neck mass in adults 1. The small mass under the skin is likely benign scar tissue resulting from previous folliculitis or skin infection, commonly associated with shaving in poor hygienic conditions. However, given the patient's age and presentation, it is essential to consider the possibility of malignancy, especially if the mass has been present for more than 2 weeks without significant fluctuation, or if it is fixed to adjacent tissues, firm, larger than 1.5 cm, or has ulceration of the overlying skin 1. Selenium sulfide (available as Selsun shampoo 2.5%) can be applied to the affected area daily for 10 minutes, then rinsed off, for 2 weeks to help reduce any associated bacterial or fungal colonization. According to the American College of Radiology Appropriateness Criteria, imaging may be requested in adult patients with a palpable neck mass to determine whether a discrete mass or abnormal lymph node is present, and to identify associated findings that may not be palpable 1. In this case, a contrast-enhanced neck CT or MRI may be more appropriate than an ultrasound, especially if the patient is deemed to be at increased risk for malignancy, as recommended by the American Academy of Otolaryngology-Head and Neck Surgery 1. Ultimately, a thorough history, physical examination, and targeted diagnostic tests, such as fine-needle aspiration or imaging, should be used to determine the underlying cause of the neck mass and guide further management. Improving shaving hygiene with clean razors, warm water preparation, and antiseptic aftershave can prevent future occurrences of folliculitis and subsequent scar tissue formation. If the diagnostic workup reveals a benign condition, such as simple scar tissue, no further intervention may be necessary beyond monitoring for changes in size or appearance.

From the FDA Drug Label

CLINICAL PHARMACOLOGY: Selenium sulfide appears to have a cytostatic effect on cells of the epidermis and follicular epithelium, reducing corneocyte production. INDICATIONS AND USAGE: For treatment of tinea versicolor, seborrheic dermatitis of scalp and treatment of dandruff.

The patient's complaint of knots or bumps under the skin, likely scar tissue, does not match the indications for selenium sulfide, which are for treatment of tinea versicolor, seborrheic dermatitis of scalp, and dandruff.

• The prescription of selenium sulfide is not supported by the drug label for this patient's condition.
• An ultrasound of the neck may be necessary to further evaluate the patient's complaint, but the use of selenium sulfide is not justified based on the provided information 2.

From the Research

Assessment and Diagnosis

• The patient presented with complaints of knots or bumps under the skin, and a small mass under the skin was noticed upon assessment, likely scar tissue.
• The patient insisted on having an ultrasound, which was prescribed along with selenium sulfide.

Role of Ultrasound in Diagnosis

• Ultrasound is an ideal triaging tool for superficial soft tissue masses, as it is inexpensive, readily available, well tolerated, and safe 3.
• High-resolution ultrasound can identify and exclude benign lesions such as superficial lipomas and ganglia, and can also distinguish pseudomasses from tumoral masses using specific signs 4.
• Ultrasound can provide detailed information about the lesion location, characterization, vascularity, and compressibility, guiding further investigation 5.

Diagnostic Testing and Evaluation

• Diagnostic testing is a cornerstone in determining the underlying issue for any symptoms seen in a patient, and provides evidence to guide healthcare providers in decision-making 6.
• A full and systematic ultrasound assessment is necessary for evaluating soft-tissue palpable lesions, including grayscale, color- and power-Doppler, spectral-Doppler, and possibly elastography facilities 7.
• Second-level options, such as magnetic resonance imaging, percutaneous fine-needle aspiration or biopsy, and surgical-excision biopsy, may be reserved for indeterminate cases or those suspected malignant at initial ultrasound 7.