About Jedidiah Leaf, MD

Assistant Professor
Emergency Medicine
University of Texas Southwestern

SAEM Clinical Images Series: Red Rash on My Legs


A 23-year-old female with no known past medical history presented with a rash concentrated on her legs, with a few areas on her arms and chest. The rash began the day before presentation when she became overheated while wearing sweatpants in 104°F weather. The rash was mildly pruritic but not painful. She denied any prior reaction to her sweatpants that she has had for several months. She denied any new soap or cosmetic use, prior rash, allergy, or medication use. Her review of systems and past medical history were negative.

Vitals: Normal

Skin: An erythematous papular rash is concentrated and symmetric on her lower extremities. There are a few sparse lesions on her arms, thorax, and abdomen with sparing of the palms, soles, and face. No pustules or vesicles are noted. There is no scale or crust. No other skin lesions are present. The rest of the examination is normal.


Miliaria, or prickly heat (heat rash).

Miliaria, also known as prickly heat or heat rash, is caused by blocked eccrine sweat glands and ducts. Exposure to heat with sweating causes eccrine sweat to pass into the dermis or epidermis causing a rash. It is common in warm and humid climates during the summer months. It can affect up to 30% of adults living in hot and humid conditions. It may present as vesicles, papules, or pustules depending on the depth of the eccrine gland obstruction. In adults the rash is most likely seen where clothes rub on the skin. Infants and children typically have lesions on the upper trunk, neck, and head. Miliaria is a clinical diagnosis. Treatment involves measures to reduce sweating and exposure to hot and humid conditions. Air conditioning and the reduced humidity of indoor environments are helpful. If significant inflammation is present with pruritis, some improvement can be seen with 0.1% triamcinolone topically, though ointment should be avoided and only cream or lotion applied.

Take-Home Points

  • Miliaria, or prickly heat, is caused by sweating and blocked eccrine sweat glands.
  • Treatment involves retreating to cool, indoor environments.
  • Triamcinolone 0.1% cream or lotion may reduce pruritis.
  • Guerra KC, Toncar A, Krishnamurthy K. Miliaria. 2023 Aug 8. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan–. PMID: 30725861.

By |2024-03-26T10:26:51-07:00Apr 1, 2024|Dermatology, SAEM Clinical Images|

SAEM Clinical Images Series: Back Lesion

skin lesion

An 18-year-old-female with no known past medical history presented with a lesion on her back that had been present and enlarging for five months. It was not painful unless she touched it, and then only mildly tender. She denied any known cause, wound, prior rash, or other lesions. Her review of systems and past medical history were negative.

Vitals: Normal

Skin: An erythematous lenticular, or biconvex, lesion with distinct borders is noted at the left posterior thorax below the scapula. It is soft with some slight nodularity on palpation, and only mild tenderness noted. There is no fluctuance. No other skin lesions are present. The rest of the examination is normal.

Ultrasound reveals a 1.7 x 0.8 x 1.1 cm superficial soft tissue mass inferior to the scapula on the left thorax.

CT scan of the chest confirms no intrathoracic extension or other lesions.

Biopsy is the next appropriate step. The lesion does not appear to be infectious, either viral, bacterial, or fungal. Furthermore, it has no appearance of an inflammatory reaction that would benefit from topical steroids. The differential includes a cystic structure, neurofibroma, or malignancy. Because of the concern for malignancy, a biopsy was performed in the emergency department after the ultrasound and CT scan confirmed there was no extension into the thorax. The biopsy revealed a pilomatrixoma, or pilomatricoma. Pilomatrixoma is a superficial benign skin tumor that arises from hair follicle matrix cells. They commonly occur in the first two decades of life with a mean age of 17 years. The most common presentation is an asymptomatic, firm, slowly growing mobile nodule. However, only 16% are accurately diagnosed on clinical examination. This case reveals the wide variation in visual presentation and confirms the inability to diagnose the lesion at the bedside. Complete surgical excision is curative.

Take-Home Points

  • Unknown skin lesions, with concern for malignancy, should be diagnosed by biopsy.
  • Pilomatrixoma is rarely diagnosed at the bedside.
  • Jones CD, Ho W, Robertson BF, Gunn E, Morley S. Pilomatrixoma: A Comprehensive Review of the Literature. Am J Dermatopathol. 2018 Sep;40(9):631-641. doi: 10.1097/DAD.0000000000001118. PMID: 30119102.

By |2024-01-28T21:32:23-08:00Feb 2, 2024|Dermatology, SAEM Clinical Images|

SAEM Clinical Images Series: Face and Chest Rash

chicken pox

A 23-year-old female with a past medical history of asthma presented with a rash that began five days ago on her face and spread to her chest. The lesions are painful and pruritic, spreading slightly to her extremities. She noted a slight sore throat and nasal congestion. She denied any known fever and had no known vaginal or oral lesions. She has a 5-year-old daughter at home with no known symptoms. She is sexually active with one male partner who has no rash or illness. She is vaccinated for COVID-19. She is unsure of childhood illnesses and believes she was never properly immunized as a child in Central America.

Vitals: BP 110/55; Temperature 37°C; pulse ox 97%

Skin: Face, thorax, and extremity papules are noted with an erythematous base, some vesicular, others with occasional crust or scabs. No dermatomal distribution. There is relative sparing of extremities with more lesions noted on the trunk and face. Negative Nikolsky sign. Otherwise, no other findings on physical examination.


Herpes varicella-zoster, or chickenpox, is a viral infection transmitted by airborne droplets and direct contact. Before immunization, 90% of cases occurred in children. While primary infection in children is generally benign, adult and infant infections can have severe complications including encephalitis and pneumonia. Erythematous vesicular lesions appear in successive crops typically starting on the face and spreading to the trunk. Extremities usually have more minor involvement with sparing of palms and soles. Vesicles progress quickly to crusted erosions in 8-to-12-hour periods. Treatment should focus on symptomatic care.

Antivirals can slow the severity of the course if given within 24 hours of the onset. Severely immunocompromised patients should receive acyclovir 10 mg/kg IV every 8 hours for 7 to 10 days.

Take-Home Points

  • Chickenpox presents with several “crops” of lesions: papules, vesicles, and scabs.
  • Adult primary disease is not common and is more severe than pediatric illness.
  • Antivirals are not indicated after the first day of illness in immunocompetent adults with mild to moderate disease.

  • Gomez-Gutierrez AK, Flores-Camargo AA, Casillas Fikentscher A, et al. Primary varicella or herpes zoster? An educational case report from the primary care clinic. Cureus Apr 2022;14(4):e23732.
  • Hughes CM, Liu L, Davidson WB, et al. A Tale of Two Viruses: Coinfections of Monkeypox and Varicella Zoster Virus in the Democratic Republic of Congo. Am J Trop Med Hyg. 2020 Dec 7;104(2):604-611. doi: 10.4269/ajtmh.20-0589. PMID: 33289470
  • Kennedy PGE, Gershon AA. Clinical Features of Varicella-Zoster Virus Infection. Viruses. 2018 Nov 2;10(11):609. doi: 10.3390/v10110609. PMID: 30400213
  • Wolff K, Johnson RA Saavedra AP. Fitzpatrick’s Color Atlas of Clinical Dermatology. 7th ed. McGraw Hill. 2013:673-675.

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