What is Poison Oak?
Poison oak is a form of allergic contact dermatitis that afflicts those exposed to the plant poison oak. Poison oak secretes an oil called urushiol that binds on contact with skin cells, prompting the body to attempt to reject them as foreign invaders. This subversion of the body’s self-defense mechanisms is what defines it as an allergic reaction, as opposed to an irritant reaction, which is caused by simple exposure.
Poison oak is a fairly common skin ailment in the United States, where poison oak is native. It is a widespread plant that is commonly found in national parks and other areas of protected wilderness, and it frequently sprouts on public property as well.
Who gets Poison Oak?
Roughly everyone is equally susceptible to poison oak over time. All but an average of one in five people are subjected to a severe rash upon their first exposure to poison oak and, subsequently, the urushiol oil that causes the allergic reaction. Those that are not affected by their first or second exposure are generally sensitized enough to urushiol oil that they will rapidly begin suffering symptoms shortly thereafter.
Because poison oak causes an allergic reaction, those with stronger immune systems will be more rapidly and severely affected. However, there are no other predisposing factors that make one more likely to suffer from poison oak. Vacationers and those unaware of poison oak’s appearance and risk are the most frequently affected. Those that work outdoors or in the wilderness are likely to suffer from urushiol exposure at some point or other, but are also likely to take and be aware of the necessary precautions to avoid being affected.
What causes Poison Oak?
Poison oak is caused by a defense mechanism within the poison oak plant itself. Poison oak leaves secrete a fine, barely-tangible substance called urushiol oil. Urushiol oil is an allergen that binds on contact with skin cells, as deep as it can penetrate. This results in an immune reaction which targets the affected cells. While the intent of the immune system is to destroy a perceived pathogenic invader, the result is that the body itself sustains the attack and suffers the consequences. The consequences in this case are a bad rash and blistering, as is common between all forms of urushiol reaction.
The only true cause of poison oak itself, however, is poison oak exposure. The poison oak plant secretes the urushiol oil responsible for the resulting immune response and symptoms, and consequently, only direct skin contact can bring about an actual case of poison oak. Poison oak is not contagious, nor does it spread, nor can it remit and recur. When the immune response has run its course and the body is no longer trying to expel poison oak, the rash will be done with and will then gradually subside.
It should be noted, however, that subsequent exposures to poison oak or urushiol oil will cause more severe cases of poison oak or similar allergic reactions. This is because the immune system grows more adept at repelling poison oak with each subsequent infection, the unfortunate caveat being that the immune system attacks the infected cells, rather than the pathogen itself, which produces symptoms.
While only poison oak exposure causes poison oak, exposure to poison oak does not always cause a visible set of symptoms. This is because the immune system is not yet sensitive enough to urushiol oil and thus will not react sufficiently to cause symptoms. Poison oak may then be caused by subsequent poison oak exposure.
What does Poison Oak cause?
Poison oak causes a number of symptoms related to the skin. These symptoms are in line with the symptoms caused by poison ivy and poison sumac, as they all hold the same root of cause: urushiol oil. When urushiol oil from poison oak penetrates the skin, it binds instantly with the skin cells it comes into contact with, and this causes an immune response that then produces the various unpleasant symptoms and discomfort associated with poison oak and other urushiol-borne skin ailments.
The primary symptom of urushiol oil exposure and poison oak is pruritis, or itching. Itching is the hallmark symptom of poison oak, and is the reason it is dreaded most for. The itching is produced by the immune system’s assault on the pathogen-infected skin cells. The itching and damage caused to the infected skin cells by the immune system irritates the local nerves, causing an intense itching and burning. Scratching is frequently thought to spread this itching rash, but this is not the case. This itching comes with deep, visible redness which is frequently an indicator or precursor to the worst of the itching.
The next symptom is inflammation. Inflammation is a common element of immune responses that represent the body’s attempt to raise the temperature of a local area of skin. The raising of local temperature by even a few degrees is frequently enough to kill viral infections; this is the same principle that goes into fevers, which, problematic as they can be, are designed to be healing mechanisms of the body and natural defenses against pathogens. This inflammation tends to exacerbate the redness that the immune response already causes, and is accompanied in many cases by swelling as a result of the increased blood flow to the area.
The third symptom at hand is blistering. Blistering is a more extreme form of immune response that involves the skin bubbling over with pus. This pus contains high levels of white blood cells intended to fight off infection where it resides. Blistering tends to occur in more severe cases of poison oak, and can be quite unsightly. The pus involved in blistering is frequently mistaken for a component of the plant, and thought of as poisonous or contagious. This is not the case; the blisters contain only pus, and their rupture will not spread the rash further. Over time, the blisters will eventually rupture and drain on their own.
Blistering and scratching at the rash is likely to cause scarring to some degree. The open sores caused by ruptured blisters open a possible vulnerabilities to secondary infection, which can be a far more serious issue than poison oak itself. Secondary infections can be dangerous, and even deadly, and always carry a near-guarantee of scarring if they are not treated carefully and immediately. For this reason it is best to let blisters rupture on their own and to treat them with proper antiseptics and bandaging.
Urushiol oil is capable of causing severe lung irritation in addition to the response that it can generate on and under the skin. This is something to avoid under any circumstances, and constitutes a much more dangerous scenario than would be caused by poison oak on even the very broadest patch of skin. Even those who do not suffer from some form of chronic respiratory condition such as asthma are put at great risk by urushiol exposure to the lungs. Thankfully, such exposure is far less common and relatively difficult to bring about.
Poison oak is associated with a spreading rash very frequently, and there are a number of urban myths about how poison oak can be spread. Scratching is frequently thought of as the easiest means by which to spread poison oak, but this is erroneous. Poison oak may, however, produce the illusion of spreading. This is because different densities of urushiol oil exposure will cause presentation of symptoms at varying rates on the affected areas of skin. The most heavily affected areas will force the immune system to respond most rapidly, which will result in the first formations of the rash, and the less-heavily affected areas will follow afterward, perhaps only after the denser exposure has sensitized the immune system.
Poison oak is not contagious. Urushiol oil binds on contact with the skin. One would have to be attempting to spread poison oak deliberately to actually bring about a spread of poison oak from one individual to another. Poison oak is still frequently mistaken for contagious by many individuals. This is because poison oak has a tendency to pop up in clusters. Individuals affected by poison oak at the same time have a tendency to be in the same party and in the same area, and may well be infected by the same plant at differing times. These differing times produce rashes that present at different rates. This, coupled with differences in sensitivity creates the illusion of a rash spreading from person to person, when in reality the only mechanism in play is separate cases of the same ailment from similar sources.
How serious is Poison Oak?
Poison oak varies in severity greatly depending upon several factors. The first factor that will likely be noted is how much skin is actually affected by the poison oak. Obviously this will vary from case to case, and is modified by what skin the infected individual had covered at the time, and other factors such as how large the poison oak plant was to begin with. However, this is not the most important factor in determining how serious a case of poison oak is.
The single most important factor in deciding how serious a case of poison oak is or will be is almost always cumulative urushiol oil exposure. Subsequent exposures to urushiol oil from poison oak, poison ivy and poison sumac can cause extremely disparate degrees of symptoms. Each exposure to urushiol oil provokes an immune response, which may or may not be visible on the skin and symptomatic. However, with each subsequent exposure, the immune system learns how to better and more rapidly deal with urushiol oil and the infection at hand. Because the immune system is not attacking the oil itself, but instead the skin cells that the urushiol oil has bound itself too, a more efficient immune response means even more severe collections of symptoms. The first exposure to poison oak and urushiol oil may be completely asymptomatic. The second may result in an irksome, itching rash, and perhaps a bit of swelling. The third exposure, then, may result in a far more severe rash, worse inflammation and heavy blistering. This will continue indefinitely, to the immune system’s limit of ability to respond. Subsequent poison oak exposure is thus something to avoid, as is repeated exposure to poison ivy, poison sumac and other plants containing urushiol. All urushiol exposure is cumulative, and a case of poison ivy and another of poison oak will be no better than two cases of poison oak: both will help the immune system better fight something that it shouldn’t be fighting to begin with, resulting in more and more severe symptoms for the infected individual.
Cases of poison oak involving respiratory distress are of a different category of their own, and will not be discussed here. However, these cases, even in individuals with no respiratory history, can be far more serious than any skin infection by urushiol could ever be, and should be treated accordingly.
What does Poison Oak treatment look like?
Treatment for poison oak is first and foremost a matter of assiduous avoidance. The best way to treat poison oak is to simply not be infected to begin with. This is difficult to avoid if one does not know what to look for; a verbal description of the plant is largely insufficient to identify it in the wild, as it does not look particularly distinct from many other similar plants (aside from the fact that its name is something of a misnomer). As consequence, hikers and campers and those otherwise expecting to spend time out in the wilderness should familiarize themselves with poison oak, among other plants to avoid contact with. Even if familiarity is achieved, they should be aware of what skin they have exposed at any given time. Wearing shorts in tall grass and brush, for instance, is a bad idea for a very large number of reasons. Plants like poison ivy, poison oak and poison sumac are merely factors in why this is an exceedingly bad idea and why individuals looking to explore should be properly dressed with skin covered.
Laying and rolling in unfamiliar patches of grass and other, similar behaviors should be treated as a major safety taboo in any hiking group or party. Any meadow or patch of trees could well have plants hidden within carrying urushiol oil. Exposure to the arms and legs is the most common, but exposure to any other piece of exposed skin is just as possible, and frequently much worse. Exposure to the face, for instance, can cause irritation of the eyes and increase the likelihood of a respiratory reaction. Thus keeping contact with unfamiliar plants is the wisest course of action, as much as possible.
If exposure has already occurred, the first and best treatment is a simple cleaning with a mild soap and lukewarm running water. Cleaning the area of exposure will clear away any plant detritus or other debris that may be harboring deposits of urushiol oil, which may make the infection worse. Running water is emphasized here, as this will prevent it from simply spreading further to where it is scrubbed. This is a minor first step, but it can be rewarding, even if it will not directly alleviate any of the relevant symptoms.
The rest of the treatments are effectively symptomatic. Analgesics for the burning may help. Topical treatments are available for the itching and inflammation. Calamine lotion is frequently listed for this, and it can be quite effective. Because it is an allergic reaction, there is little that one can do but wait it out and hope the immune system plays itself out in a timely manner as the cells bound with the urushiol oil are disposed of.
There do exist other treatments to help accelerate the process and speed healing, but these can be hit or miss. Many advertise ‘all-natural’ cures to poison oak with little scientific evidence to back them up, so it is best to be wary and seek proper third-party reviews and testimonials. Several of them are known to provide varying degrees of benefit by either directly accelerating the healing and subsiding of the rash or simply easing the symptoms away.
Scratching is not an effective way to repel the itching and is not a good idea, but not for the reason it is thought of to be a bad idea. It is widely thought that scratching at a poison oak rash will spread the poison oak around and cause further difficulty, but this is not true; scratching at poison oak may damage the skin and leave it vulnerable to secondary infections, and cause scarring, but poison oak will only spread as far as its exposure allows.
Extremely severe cases of poison oak and the most powerful allergic reactions may require the intervention of a medical professional and involve prescription agents. Steroids may be used to more forcibly and rapidly reduce swelling, for instance, if the symptoms themselves become dangerous of their own accord.
How do I know if I have Poison Oak?
Poison oak can be visually identified by its symptoms with relative ease. As long as the potential for exposure has occurred sometime within twenty-four hours of the symptoms’ presentation, poison oak may be a likely cause. Other possible causes of the same symptoms, however, are poison ivy and poison sumac, which all have the same urushiol oil and can carry nearly identical symptoms. Poison oak can be positively identified by a trained medical professional as may be necessary for specific cases requiring the intervention of a trained hand and prescription medication.