Article from September, 2016

A Rash On Your Ash


Michael J. Manyak, MD, MED 92

Whether distasteful to look at or causing discomfort, rashes are annoying and possibly quite uncomfortable though rarely an emergency. But when is a rash, an annoying discomfort, something more problematic? Aye, that is the rub.

Many skin disorders result from chronic conditions, like eczema, that do not require urgent treatment while on travel unless severe or complicated by secondary bacterial infection. These were likely present before travel and known to the individual. Other rashes may have an infectious origin—fungal, bacterial, or viral. Fungal infections of the groin and thigh and athlete’s foot are contagious. Antifungal and hydrocortisone creams are the staple of management. Rashes from infectious sources can occur in the field and can be related to an environment which causes increased sweating and heat, exposure to infected travelers, and unclean public surfaces. Rashes from viral sources usually manifest from systemic infections such as measles, rubella, and chicken pox which you are at higher risk to acquire on travel if you have not had immunity or vaccinations.

Other rash-like skin disorders are related to allergies. Contact dermatitis is a skin reaction in the area of contact with something causing an allergic reaction—chemicals in tanning leather or soaps and compounds from plants like urushiol in poison ivy are classic culprits.

Some skin reactions reflect systemic allergies to foods, medications, and other substances. Hives can be a warning sign of a life-threatening severe allergic reaction known as anaphylaxis. Skin photosensitivity to certain medications (such as some classes of antibiotics and diuretics) can cause rashes when one is exposed to UV rays in sunlight.

Some apparent skin rashes are actually from insect bites with venom injected by the insect causing small lesions and itching. Bed bug bites are on the rise and can be found even in the best of hotels. These small lesions may be hard to differentiate from flea or other insect bites but bed bugs are difficult to eradicate so repeated infestations can occur. Fortunately, bed bugs do not carry diseases though excessive scratching may cause a secondary bacterial infection.

One skin infection to beware of that may have an associated localized rash is one caused by methicillin-resistant Staphylococcus aureus (MRSA). MRSA infections were initially rare and originated in hospitals but now have become a fairly common community-acquired infection. They are spread by personal contact with an infected individual or surface in the environment and are usually limited to the skin. Often there is a red, swollen, generally painful sore that may look like an infected insect bite in an area where there was a small cut or abrasion, or in areas with hair follicles (such as groin, buttock, armpit). Occasionally, MRSA infections can become more severe and develop into systemic infection, bone infections, and even pneumonia. This type of infection needs attention and treatment with broad-spectrum non-penicillin antibiotics. Strict attention to hygienic practices to include frequent hand washing is necessary to prevent spread of MRSA infections.

Divers frequently sustain cuts and abrasions which are prone to infection due to unusual bacteria in the marine environment and long periods where the affected area stays moist. Wounds not due to contact with coral should be treated with standard wound care and antibiotics if necessary. Rashes and wounds related to coral contact, however, should be thoroughly cleaned as soon as possible because they are particularly prone to infection from the large amount of reef bacteria and the retention of coral particles in the wound. Many advocate use of topical antibiotics and signs of infection should be treated early with oral antibiotics.

One other rash needs mention here in association with aquatic activities. Swimmer’s itch is an irritating rash that develops after swimming in fresh and salt water where there is contact with certain microscopic parasites that infect some birds and mammals. Also known as cercarial dermatitis, this rash is caused by an allergic reaction to the larval stage of these parasites which seek a host after being secreted by the intermediate host in the water, snails. Humans are not a suitable host but the larvae burrow into the skin causing the irritation. Though they die soon after, the swimmer has a transient rash of small pimples or blisters which may last a week or more. Treatment is primarily with hydrocortisone cream.

If you have started to scratch while reading this, like medical students studying dermatology, that is normal. Not to worry. But pay more attention in the future to your bed linen in a hotel. That could save you a lot of aggravation.


This article was published in The Explorers Journal


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