He Tried So Hard to Avoid It …

A 38-year-old man presents to dermatology with what he assumes is poison ivy: an itchy, blistery rash that usually appears in the summer, more years than not. Each year, it’s a bit worse in terms of extent and symptomatology, despite his efforts to avoid the problem altogether.

The rash pretty consistently manifests on his leg, although there are other areas of involvement. Equally predictable, at this point, is his wife’s reaction: She banishes him to the couch for fear of “catching” whatever he has.

After so many years’ experience with the condition, the patient is understandably alert to coming in contact with the offending plant. He has even taken photos of it, to demonstrate how abundantly it grows in his yard.

EXAMINATION
The patient’s lesions are classic collections of vesicles crisscrossing his legs in linear configurations. There is faint underlying erythema. Smaller but similar lesions are scattered over his arms and trunk; the patient is sure he spread the rash with his scratching.

The plant in the patient’s photos has five dart-shaped leaves with uniformly serrated margins extending from a single stem. It grows as a vine on fences and masonry. He has scrupulously avoided contact with it and therefore cannot understand how he keeps developing the rash.

What is the diagnosis?

DISCUSSION
It has been said that humor is tragedy plus time; certain skin diseases, such as shingles or poison ivy, certainly provide fodder. In the midst of an attack, however, these conditions can produce not only miserable symptoms of itching, pain, and sleeplessness, but also considerable mental anguish regarding contagion.

Repeated polls of the general public reveal an almost universal belief that poison ivy is contagious and that scratching spreads it around the body. Research, and a thorough knowledge of the pathophysiology involved, have long since disproven both concepts. So while the inclination to distance oneself from an affected person is understandable, there is actually no need to do so. For the patient, facing six weeks or more of isolation is no laughing matter (at least, until long after the fact).

This particular case highlights one other pertinent issue with poison ivy: As the photos established, the patient had carefully avoided the wrong plant. The five dart-shaped serrated leaves suggest Virginia creeper—certainly not poison ivy. This may sound like a minor issue, but it is quite possible that while the patient was steering clear of a harmless plant, he was in fact coming in contact with the one he should have been concerned about.

True poison ivy, Toxicodendron radicans, can develop as a bush, a vine that stays low to the ground, a small tree, or even a climbing vine that can reach 30 feet or higher into mature trees, especially along waterways or in low, boggy land. The vines can attain a thickness of more than 3 in and have a surface covered by tiny “rootlets,” giving them a shaggy look.

Regardless of the plant’s form, its leaves are always found in threes, protruding from the same stem. The leaves are diamond shaped, can reach a length of 10 in, and often have a single notch on the margin that is said to resemble the outline of a thumb. The plant produces white berries in late summer or early fall.

It has been estimated that the number of poison ivy plants has doubled since 1960, for at least two reasons. First, an increase in population has led to more land being cleared for housing; many properties now border woodlands, which are an ideal environment for this plant.

Second, and more surprising, poison ivy thrives in a CO₂-rich environment. Carbon dioxide in the atmosphere has increased significantly in the past 50 years and will continue to do so. Experts predict that the density of poison ivy will double again in the next 20 years as a result. The potency of the urushiol, the offending substance in the stems and leaves, is expected to increase as well.

The patient (height, 6’3” and weight, > 300 lb) was treated with a 60-mg IM injection of triamcinolone, a two-week, 40-mg taper of prednisone, and twice-daily application of betamethasone cream. This, of course, followed a discussion of the risks versus benefits of such a course of action.

TAKE-HOME LEARNING POINTS
• Climbing vines with five serrated leaves coming off the same stem are probably Virginia creeper and not poison ivy.

• Poison ivy is not contagious, cannot be spread by scratching, and is not poisonous in any way.

• The rash produced by poison ivy exposure can be severe and can last six weeks or more without treatment.

• The number of poison ivy plants has doubled in the past 50 years and is expected to double again within 20 years. The potency of the plant’s allergen is also expected to increase. 

A 38-year-old man presents to dermatology with what he assumes is poison ivy: an itchy, blistery rash that usually appears in the summer, more years than not. Each year, it’s a bit worse in terms of extent and symptomatology, despite his efforts to avoid the problem altogether.

The rash pretty consistently manifests on his leg, although there are other areas of involvement. Equally predictable, at this point, is his wife’s reaction: She banishes him to the couch for fear of “catching” whatever he has.

After so many years’ experience with the condition, the patient is understandably alert to coming in contact with the offending plant. He has even taken photos of it, to demonstrate how abundantly it grows in his yard.

EXAMINATION
The patient’s lesions are classic collections of vesicles crisscrossing his legs in linear configurations. There is faint underlying erythema. Smaller but similar lesions are scattered over his arms and trunk; the patient is sure he spread the rash with his scratching.

The plant in the patient’s photos has five dart-shaped leaves with uniformly serrated margins extending from a single stem. It grows as a vine on fences and masonry. He has scrupulously avoided contact with it and therefore cannot understand how he keeps developing the rash.

What is the diagnosis?

DISCUSSION
It has been said that humor is tragedy plus time; certain skin diseases, such as shingles or poison ivy, certainly provide fodder. In the midst of an attack, however, these conditions can produce not only miserable symptoms of itching, pain, and sleeplessness, but also considerable mental anguish regarding contagion.

Repeated polls of the general public reveal an almost universal belief that poison ivy is contagious and that scratching spreads it around the body. Research, and a thorough knowledge of the pathophysiology involved, have long since disproven both concepts. So while the inclination to distance oneself from an affected person is understandable, there is actually no need to do so. For the patient, facing six weeks or more of isolation is no laughing matter (at least, until long after the fact).

This particular case highlights one other pertinent issue with poison ivy: As the photos established, the patient had carefully avoided the wrong plant. The five dart-shaped serrated leaves suggest Virginia creeper—certainly not poison ivy. This may sound like a minor issue, but it is quite possible that while the patient was steering clear of a harmless plant, he was in fact coming in contact with the one he should have been concerned about.

True poison ivy, Toxicodendron radicans, can develop as a bush, a vine that stays low to the ground, a small tree, or even a climbing vine that can reach 30 feet or higher into mature trees, especially along waterways or in low, boggy land. The vines can attain a thickness of more than 3 in and have a surface covered by tiny “rootlets,” giving them a shaggy look.

Regardless of the plant’s form, its leaves are always found in threes, protruding from the same stem. The leaves are diamond shaped, can reach a length of 10 in, and often have a single notch on the margin that is said to resemble the outline of a thumb. The plant produces white berries in late summer or early fall.

It has been estimated that the number of poison ivy plants has doubled since 1960, for at least two reasons. First, an increase in population has led to more land being cleared for housing; many properties now border woodlands, which are an ideal environment for this plant.

Second, and more surprising, poison ivy thrives in a CO₂-rich environment. Carbon dioxide in the atmosphere has increased significantly in the past 50 years and will continue to do so. Experts predict that the density of poison ivy will double again in the next 20 years as a result. The potency of the urushiol, the offending substance in the stems and leaves, is expected to increase as well.

The patient (height, 6’3” and weight, > 300 lb) was treated with a 60-mg IM injection of triamcinolone, a two-week, 40-mg taper of prednisone, and twice-daily application of betamethasone cream. This, of course, followed a discussion of the risks versus benefits of such a course of action.

TAKE-HOME LEARNING POINTS
• Climbing vines with five serrated leaves coming off the same stem are probably Virginia creeper and not poison ivy.

• Poison ivy is not contagious, cannot be spread by scratching, and is not poisonous in any way.

• The rash produced by poison ivy exposure can be severe and can last six weeks or more without treatment.

• The number of poison ivy plants has doubled in the past 50 years and is expected to double again within 20 years. The potency of the plant’s allergen is also expected to increase. 

A 38-year-old man presents to dermatology with what he assumes is poison ivy: an itchy, blistery rash that usually appears in the summer, more years than not. Each year, it’s a bit worse in terms of extent and symptomatology, despite his efforts to avoid the problem altogether.

The rash pretty consistently manifests on his leg, although there are other areas of involvement. Equally predictable, at this point, is his wife’s reaction: She banishes him to the couch for fear of “catching” whatever he has.

After so many years’ experience with the condition, the patient is understandably alert to coming in contact with the offending plant. He has even taken photos of it, to demonstrate how abundantly it grows in his yard.

EXAMINATION
The patient’s lesions are classic collections of vesicles crisscrossing his legs in linear configurations. There is faint underlying erythema. Smaller but similar lesions are scattered over his arms and trunk; the patient is sure he spread the rash with his scratching.

The plant in the patient’s photos has five dart-shaped leaves with uniformly serrated margins extending from a single stem. It grows as a vine on fences and masonry. He has scrupulously avoided contact with it and therefore cannot understand how he keeps developing the rash.

What is the diagnosis?

DISCUSSION
It has been said that humor is tragedy plus time; certain skin diseases, such as shingles or poison ivy, certainly provide fodder. In the midst of an attack, however, these conditions can produce not only miserable symptoms of itching, pain, and sleeplessness, but also considerable mental anguish regarding contagion.

Repeated polls of the general public reveal an almost universal belief that poison ivy is contagious and that scratching spreads it around the body. Research, and a thorough knowledge of the pathophysiology involved, have long since disproven both concepts. So while the inclination to distance oneself from an affected person is understandable, there is actually no need to do so. For the patient, facing six weeks or more of isolation is no laughing matter (at least, until long after the fact).

This particular case highlights one other pertinent issue with poison ivy: As the photos established, the patient had carefully avoided the wrong plant. The five dart-shaped serrated leaves suggest Virginia creeper—certainly not poison ivy. This may sound like a minor issue, but it is quite possible that while the patient was steering clear of a harmless plant, he was in fact coming in contact with the one he should have been concerned about.

True poison ivy, Toxicodendron radicans, can develop as a bush, a vine that stays low to the ground, a small tree, or even a climbing vine that can reach 30 feet or higher into mature trees, especially along waterways or in low, boggy land. The vines can attain a thickness of more than 3 in and have a surface covered by tiny “rootlets,” giving them a shaggy look.

Regardless of the plant’s form, its leaves are always found in threes, protruding from the same stem. The leaves are diamond shaped, can reach a length of 10 in, and often have a single notch on the margin that is said to resemble the outline of a thumb. The plant produces white berries in late summer or early fall.

It has been estimated that the number of poison ivy plants has doubled since 1960, for at least two reasons. First, an increase in population has led to more land being cleared for housing; many properties now border woodlands, which are an ideal environment for this plant.

Second, and more surprising, poison ivy thrives in a CO₂-rich environment. Carbon dioxide in the atmosphere has increased significantly in the past 50 years and will continue to do so. Experts predict that the density of poison ivy will double again in the next 20 years as a result. The potency of the urushiol, the offending substance in the stems and leaves, is expected to increase as well.

The patient (height, 6’3” and weight, > 300 lb) was treated with a 60-mg IM injection of triamcinolone, a two-week, 40-mg taper of prednisone, and twice-daily application of betamethasone cream. This, of course, followed a discussion of the risks versus benefits of such a course of action.

TAKE-HOME LEARNING POINTS
• Climbing vines with five serrated leaves coming off the same stem are probably Virginia creeper and not poison ivy.

• Poison ivy is not contagious, cannot be spread by scratching, and is not poisonous in any way.

• The rash produced by poison ivy exposure can be severe and can last six weeks or more without treatment.

• The number of poison ivy plants has doubled in the past 50 years and is expected to double again within 20 years. The potency of the plant’s allergen is also expected to increase.