Reviewing Summer Rashes: How Providers Can Spot and Treat

Mosquito bite on a patient with skin of color

Image courtesy of Block

Long summer days mean spending more time outdoors, which can also increase the risk of summer rashes, something all providers have experienced at least once, if not more, in the dermatology clinic.

From bug bites to poison ivy, the skin can be exposed to a large spectrum of trouble while patients spend extended time outside. The issue is that these reactions can take patients by surprise, as some can be delayed and not noticed immediately. However, some reactions can be life-threatening with symptoms such as lips, tongue, and throat swelling, difficulty breathing, muscle spasms, or irregular heart palpitations, and should be treated immediately in the emergency room.

It is not uncommon for patients to want to seek medical care for their summer rash after such exposures and see their primary care provider (PCP), but later end up in urgent care or the emergency room before they are seen at the dermatology clinic, where often a patient cannot be seen immediately. According to the Greater Access for Patients Partnership (GAPP), "Appointment wait times have increased by 46% since 2009," it can take 56 days to be seen by a dermatologist.¹ However, if patients know they can be seen by a dermatology PA or NP sooner, they could avoid the PCP, urgent care, or the emergency room altogether and receive appropriate treatment immediately for the rash.

By understanding how one can protect themselves, patients can easily prevent common skin concerns seen during the summer months. However, we can educate our patients and non-dermatology colleagues on prevention, recognition, and treatment before they lead to unwanted effects. Below are a few of the most common summer exposures encountered at a dermatology clinic.

Figure 1. Spider bite

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Figure 2. Erythema migrans from tick

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Bug Stings and Bites

Exposure to bees, wasps, mosquitos, spiders, ticks, and fire ants can ruin anybody's day. These are known as arthropod assaults which all produce venoms that the body reacts to. "Venoms consist of toxic components that are delivered to their victims via bites or stings. Venoms also represent a major class of allergens in humans."²

These Type II cell-mediated immune responses are immediate. They can cause itch, redness, and swelling, leading to pain and discomfort because of the release of "beneficial pro-inflammatory mediators, toxin-neutralizing enzymes, and helminth-killing toxins"³ (Figure 1). Typically, all bites can appear like the example from Figure 1, and treatments with over-the-counter remedies are enough, but secondary infections are also a risk and should be monitored for. However, if the culprit is not identified and other reactions occur, they must be treated immediately.

Anaphylaxis is a risk and can happen quickly after the assault, but, other effects can still appear. For example, the black widow can cause severe muscle spasms and other serious side effects many hours later, and the brown recluse spider can cause a deep skin ulcer 1-2 weeks afterward. Finally, "erythema migrans rashes occur in 70%-80% of infected patients, with onset between 3-30 days (average of 7 days) after being bitten by a tick carrying Borrelia burgdorferi, or less commonly, Borrelia mayonii"⁴ (Figure 2). These types of exposures need immediate attention and intervention.

Figure 3. Poison ivy

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Plant-Related Rashes

"About 85% of the population is allergic to poison ivy, poison sumac, or poison oak, and about 10% to 15% are extremely allergic."⁵ It is always best to start at the source and recognize these plants to avoid them altogether. These plants are the most common allergic reaction in the US, and approximately 50 million Americans are affected yearly.⁵ 

The allergen is urushiol, an oil found within the plants and when skin is directly or indirectly exposed (ie, exposure from a secondary source such as animal fur, clothing, or other materials) (Figure 3). It can take 2 to 10 days before the rash appears and is not contagious, but the allergic reaction continues after washing off the oil. The response is Type IV hypersensitivity which is delayed compared to the Type II found after an arthropod assault. "A Type IV hypersensitivity reaction is mediated by T cells that provoke an inflammatory reaction against exogenous or endogenous antigens," which can cause severe itch and inflammation (aka contact dermatitis).⁶ The rash can last several weeks and typically needs an Rx topical steroid. In extreme cases, patients may need an oral steroid.

Miliaria (Prickly Heat)

Figure 4. Miliaria

Image courtesy of DermNet

Summer heat can reach extreme temperatures and humidity, making one sweat more than usual. Wearing tight clothing can produce small, pruritic papules in the affected areas (Figure 4). They are seen on the buttocks, posterior legs, and trunk due to occlusion of the eccrine sweat glands on the skin. Patients complain of the unsightly rash and often state it feels "prickly" because it is affected deeper in the skin. "The types of heat rash are classified according to how deep the sweat is trapped in the skin."⁷

Signs and symptoms can vary from mild and asymptomatic to deep and painful. The best treatment is to keep the skin cool (using a cool compress) and avoid wearing tight clothing, along with a gentle cleanser and over-the-counter topical corticosteroid.

Polymorphic Light Eruption (PLE)

Figure 5. Polymorphic light eruption

Image courtesy of DermNet

PLE is a common condition seen in dermatology clinics in which the skin damage from sun exposure can "fool" the immune system into attacking what it believes to be "foreign" components damaging the skin. Typically, this is seen in sun-exposed areas with a pruritic rash at the beginning of summer (Figure 5). A true PLE should lessen with subsequent exposures, if not, one should consider another diagnosis like lupus. In general, patients should practice sun protection all summer long. Treatment includes a solid regimen of sun protection practices and topical prescription steroids to alleviate the itch; however, OTC anti-itch products can also be helpful.

Cercarial Dermatitis (Swimmers Itch)

Figure 6. Swimmer's itch

Image courtesy of DermNet

Caused by a parasite known as schistosomes that live in ponds, lakes, and oceans, this pesky summer rash is a nuisance and unsightly (Figure 6). The parasite stems from infected animals such as snails, ducks, geese, seagulls, and swans. It causes an allergic reaction in humans from the feces of these animals, specifically from the larvae burrowing into the skin. "Within minutes to days after swimming in contaminated water, you may experience tingling, burning, or itching of the skin. Small reddish pimples appear within twelve hours.⁸ 

It is not contagious within humans and typically resolves after one week. Still, treatments such as OTC hydrocortisone or other anti-itch remedies, cool compress, oatmeal baths, cool compresses, and Epsom salt baths can alleviate discomfort. The best way to prevent cercarial dermatitis is by rinsing immediately after swimming and choosing swimming spots wisely, as signs can be posted about the increased risk.

Seabather's Eruption

Figure 7. Seabather's eruption

Image courtesy of DermNet

"Seabather's eruption (SBE), also known as "Sea Lice," is pruritic dermatitis found in a bathing suit distribution and at sites of friction after bathing in the ocean." Two saltwater species of Cnidarians cause the eruption: the thimble Jellyfish (Linuche unguiculata) and a sea anemone (Edwardsiella lineata).⁹

This rash differs from cercarial dermatitis because the species is entrapped under the bathing suit and is typically experienced during swimming or immediately after leaving the water (Figure 7). The best treatments include washing the swimsuit and rinsing immediately after exposure or removing the swimsuit as soon as possible. Other therapies include the same as exposure to cercarial dermatitis.

Sunburn

Figure 8. Sunburn

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Though a sunburn (Figure 8) is not technically a rash, it is good to include this in the summer rash section as "each year, about one third of US adults experience at least 1 sunburn, and sunburn prevalence is even higher among certain demographic groups, including adults aged <30 years (47.2%)."¹⁰

A sunburn can cause dryness, leading to skin pruritus, hence the summer rash inclusion. All medical providers should discuss sun safety protocols with patients. Safe sun practices should occur across all disciplines of medical practice as it can cause an increased risk for skin cancer and other patient concerns, such as discoloration, fine lines, and wrinkles. Wearing a broad-spectrum SPF of 30 or higher and reapplying every 2 hours or after sweating or swimming is essential to avoid sunburn altogether. To treat, use a cool compress, aloe vera, moisturization, and an OTC hydrocortisone or other anti-itch medications for itching.

Sun Sensitivity From Medications (OTC and Rx)

Certain medications can lower the sunburn threshold because they are known as photosensitizers. Again, sun safety is the most crucial educational piece practitioners of all disciplines should follow. Unfortunately, many patients do not read the package inserts and come into the dermatology clinic complaining of a pruritic red rash or sun sensitivity, not knowing they resulted from their medications. Prime suspects include thiazide diuretics, antihistamines, contraceptive pills, antibiotics, isotretinoin, and nonsteroidal anti-inflammatory drugs like ibuprofen. The key is prevention in the first place by UV safety precautions provided during the office visit when such medications are advised. Treatment includes the same as when treating a sunburn.

Additional bug bite example. Arthropod assault

Image courtesy of Block

Continued Monitoring

In the end, becoming familiar with the typical summer rashes will allow the non-dermatology practitioner to provide the appropriate guidelines for optimal patient treatment. Informing patients and providing them with tips to avoid most rashes altogether is always the best approach. All dermatology clinics should offer a 911 slot for these types of rashes and be a standard for all dermatology practices for the best patient care.

Renata Block, MMS, PA-C, is a board-certified physician assistant at Advanced Dermatology & Aesthetic Medicine in Chicago, Illinois.

References

1. Patients are waiting: America’s dermatology appointment wait time crisis, Greater Access for Patients Partnership. May 2019. Accessed August 3, 2023; https://cdn.ymaws.com/www.dermpa.org/resource/resmgr/GAPP_Wait_Time_Report_final.pdf
2. Palm NW, Rosenstein RK, Yu S, Schenten DD, Florsheim E, Medzhitov R. Bee venom phospholipase A2 induces a primary type 2 response that is dependent on the receptor ST2 and confers protective immunity. Immunity. 2013 Nov 14;39(5):976-85. doi: 10.1016/j.immuni.2013.10.006.
3. Hammand H, Lambrecht B. Barrier epithelial cells and the control of type 2 immunity. Immunity. 2015 July. doi: /10.1016/j.immuni.2015.07.007.
4. Lyme disease rashes. NAPNAP Knows Lyme. Updated 2023. Accessed August 3, 2023. https://napnapknowslyme.org/for-providers/lyme-disease-rashes/
5. Poison ivy, sumac, and oak. American Skin Association. Updated 2020. Accessed August 3, 2023. https://www.americanskin.org/resource/poisonivy.php
6. Marwa K, Kondamudi NP. Type IV hypersensitivity reaction. StatPearls. Treasure Island (FL): StatPearls Publishing; March 6, 2023. Accessed August 3, 2023.
7. Heat rash: symptoms and causes. Mayo Clinic. May 6, 2022. Accessed August 3, 2023. https://www.mayoclinic.org/diseases-conditions/heat-rash/symptoms-causes/syc-20373276
8. Swimmer’s itchFAQs. Centers for Disease Control and Prevention. Updated September 2, 2020. Accessed August 3, 2023. https://www.cdc.gov/parasites/swimmersitch/faqs.html
9. Prohaska J, Jamal Z, Tanner LS. Seabatherseruption. In: StatPearls. Treasure Island (FL): StatPearls Publishing; January 2023. Accessed August 3, 2023
10. Holman DM, Ragan KR, Julian AK, Perna FM. The context of sunburn among US adults: common activities and sun protection behaviors. Am J Prev Med. 2021;60(5): e213-e220. doi:10.1016/j.amepre.2020.12.011.