The 15-Year Itch

A 58-year-old woman presents to dermatology with a 15-year history of an itchy rash on her left leg. A native of India, she has been in this country for more than 20 years and enjoys generally good health.

But about 15 years ago, she experienced some personal problems that caused great stress. About that same time, she developed a small rash on her left leg, which she began to scratch.

Over time, the lesion has become larger and more pruritic, prompting her to scratch and rub it more. Lately, she has started to use a hairbrush to scratch it. The itching has taken on a whole new level of intensity.

Her primary care provider referred her to a wound care clinic, where her lesion was treated with twice-weekly whirlpool therapy, followed by debridement and dressing with a zinc oxide–based paste. Although this calmed the affected site a bit, when treatment ceased, the rash flared again.

EXAMINATION
The patient has type IV skin, consistent with her origins. The lesion is an impressive, elongated oval plaque measuring about 20 x 10 cm. It covers most of the anterolateral portion of her left leg and calf.

An underlying area of brown macular hyperpigmentation extends an additional 2 to 3 cm around the periphery of the plaque. The central area is slightly edematous, quite pink, and shiny. No focal breaks in the skin are observed. There is no increased warmth or tenderness on palpation.

What is the diagnosis?

DISCUSSION
This complaint and its location are typical of an extremely common dermatologic entity called lichen simplex chronicus (LSC), formerly known as neurodermatitis. All cases of LSC start with a relatively minor, itchy trigger—such as dry skin, eczema, or a bug bite—that the patient begins to scratch or rub. This has the effect of lowering the threshold for itching by making the nerves more numerous and sensitive; the patient then reacts by scratching or rubbing even more. As a result, the epidermal layer thickens and, particularly in patients with darker skin, postinflammatory hyperpigmentation develops.

The patient will persistently respond to the itching by scratching, a reaction that becomes habitual (and in some cases, even pleasurable) and perpetuates the cycle. Although the original insult has long since resolved, the problem has taken on a life of its own.

In the 15-year history of this lesion, the patient had seen a number of clinicians but, incredibly, never a dermatology provider. She had taken several courses of oral antibiotics, used triple-antibiotic ointment, and tried tea tree oil, emu oil, antifungal creams, and most recently, topical triamcinolone cream—the last of which helped a bit.

The actual solution to the problem is utterly simple, at least in concept: Stop scratching. But there’s the rub—the impulse to scratch is quite powerful, and habits are difficult to break.

That’s where we intervened, with the use of a stronger topical steroid ointment (clobetasol 0.05% bid) on an occlusive dressing (eg, an elastic bandage wrap), which potentiates the steroid and serves as a barrier to the patient’s scratching. A soft cast (eg, an Unna boot) would accomplish the same thing but is more troublesome to apply.

Given this patient’s skin type, this area of her leg will always be discolored. She should, however, be able to control the problem from now on. If this treatment attempt were to fail, a biopsy would be needed to rule out other diagnostic possibilities, such as psoriasis or lichen planus.

TAKE-HOME LEARNING POINTS
• Lichen simplex chronicus (LSC) is quite common, especially on the anterolateral leg.

• LSC is always secondary to an original trigger, such as xerosis, eczema, bug bite, or even psoriasis.

• The chronicity of the problem, sometimes extreme (as in this case), is not only common but often diagnostic.

• Postinflammatory color changes, especially on darker skinned individuals, are common with LSC.

• Other common areas for LSC include the scrotum/vulvae and nuchal scalp. 

A 58-year-old woman presents to dermatology with a 15-year history of an itchy rash on her left leg. A native of India, she has been in this country for more than 20 years and enjoys generally good health.

But about 15 years ago, she experienced some personal problems that caused great stress. About that same time, she developed a small rash on her left leg, which she began to scratch.

Over time, the lesion has become larger and more pruritic, prompting her to scratch and rub it more. Lately, she has started to use a hairbrush to scratch it. The itching has taken on a whole new level of intensity.

Her primary care provider referred her to a wound care clinic, where her lesion was treated with twice-weekly whirlpool therapy, followed by debridement and dressing with a zinc oxide–based paste. Although this calmed the affected site a bit, when treatment ceased, the rash flared again.

EXAMINATION
The patient has type IV skin, consistent with her origins. The lesion is an impressive, elongated oval plaque measuring about 20 x 10 cm. It covers most of the anterolateral portion of her left leg and calf.

An underlying area of brown macular hyperpigmentation extends an additional 2 to 3 cm around the periphery of the plaque. The central area is slightly edematous, quite pink, and shiny. No focal breaks in the skin are observed. There is no increased warmth or tenderness on palpation.

What is the diagnosis?

DISCUSSION
This complaint and its location are typical of an extremely common dermatologic entity called lichen simplex chronicus (LSC), formerly known as neurodermatitis. All cases of LSC start with a relatively minor, itchy trigger—such as dry skin, eczema, or a bug bite—that the patient begins to scratch or rub. This has the effect of lowering the threshold for itching by making the nerves more numerous and sensitive; the patient then reacts by scratching or rubbing even more. As a result, the epidermal layer thickens and, particularly in patients with darker skin, postinflammatory hyperpigmentation develops.

The patient will persistently respond to the itching by scratching, a reaction that becomes habitual (and in some cases, even pleasurable) and perpetuates the cycle. Although the original insult has long since resolved, the problem has taken on a life of its own.

In the 15-year history of this lesion, the patient had seen a number of clinicians but, incredibly, never a dermatology provider. She had taken several courses of oral antibiotics, used triple-antibiotic ointment, and tried tea tree oil, emu oil, antifungal creams, and most recently, topical triamcinolone cream—the last of which helped a bit.

The actual solution to the problem is utterly simple, at least in concept: Stop scratching. But there’s the rub—the impulse to scratch is quite powerful, and habits are difficult to break.

That’s where we intervened, with the use of a stronger topical steroid ointment (clobetasol 0.05% bid) on an occlusive dressing (eg, an elastic bandage wrap), which potentiates the steroid and serves as a barrier to the patient’s scratching. A soft cast (eg, an Unna boot) would accomplish the same thing but is more troublesome to apply.

Given this patient’s skin type, this area of her leg will always be discolored. She should, however, be able to control the problem from now on. If this treatment attempt were to fail, a biopsy would be needed to rule out other diagnostic possibilities, such as psoriasis or lichen planus.

TAKE-HOME LEARNING POINTS
• Lichen simplex chronicus (LSC) is quite common, especially on the anterolateral leg.

• LSC is always secondary to an original trigger, such as xerosis, eczema, bug bite, or even psoriasis.

• The chronicity of the problem, sometimes extreme (as in this case), is not only common but often diagnostic.

• Postinflammatory color changes, especially on darker skinned individuals, are common with LSC.

• Other common areas for LSC include the scrotum/vulvae and nuchal scalp. 

A 58-year-old woman presents to dermatology with a 15-year history of an itchy rash on her left leg. A native of India, she has been in this country for more than 20 years and enjoys generally good health.

But about 15 years ago, she experienced some personal problems that caused great stress. About that same time, she developed a small rash on her left leg, which she began to scratch.

Over time, the lesion has become larger and more pruritic, prompting her to scratch and rub it more. Lately, she has started to use a hairbrush to scratch it. The itching has taken on a whole new level of intensity.

Her primary care provider referred her to a wound care clinic, where her lesion was treated with twice-weekly whirlpool therapy, followed by debridement and dressing with a zinc oxide–based paste. Although this calmed the affected site a bit, when treatment ceased, the rash flared again.

EXAMINATION
The patient has type IV skin, consistent with her origins. The lesion is an impressive, elongated oval plaque measuring about 20 x 10 cm. It covers most of the anterolateral portion of her left leg and calf.

An underlying area of brown macular hyperpigmentation extends an additional 2 to 3 cm around the periphery of the plaque. The central area is slightly edematous, quite pink, and shiny. No focal breaks in the skin are observed. There is no increased warmth or tenderness on palpation.

What is the diagnosis?

DISCUSSION
This complaint and its location are typical of an extremely common dermatologic entity called lichen simplex chronicus (LSC), formerly known as neurodermatitis. All cases of LSC start with a relatively minor, itchy trigger—such as dry skin, eczema, or a bug bite—that the patient begins to scratch or rub. This has the effect of lowering the threshold for itching by making the nerves more numerous and sensitive; the patient then reacts by scratching or rubbing even more. As a result, the epidermal layer thickens and, particularly in patients with darker skin, postinflammatory hyperpigmentation develops.

The patient will persistently respond to the itching by scratching, a reaction that becomes habitual (and in some cases, even pleasurable) and perpetuates the cycle. Although the original insult has long since resolved, the problem has taken on a life of its own.

In the 15-year history of this lesion, the patient had seen a number of clinicians but, incredibly, never a dermatology provider. She had taken several courses of oral antibiotics, used triple-antibiotic ointment, and tried tea tree oil, emu oil, antifungal creams, and most recently, topical triamcinolone cream—the last of which helped a bit.

The actual solution to the problem is utterly simple, at least in concept: Stop scratching. But there’s the rub—the impulse to scratch is quite powerful, and habits are difficult to break.

That’s where we intervened, with the use of a stronger topical steroid ointment (clobetasol 0.05% bid) on an occlusive dressing (eg, an elastic bandage wrap), which potentiates the steroid and serves as a barrier to the patient’s scratching. A soft cast (eg, an Unna boot) would accomplish the same thing but is more troublesome to apply.

Given this patient’s skin type, this area of her leg will always be discolored. She should, however, be able to control the problem from now on. If this treatment attempt were to fail, a biopsy would be needed to rule out other diagnostic possibilities, such as psoriasis or lichen planus.

TAKE-HOME LEARNING POINTS
• Lichen simplex chronicus (LSC) is quite common, especially on the anterolateral leg.

• LSC is always secondary to an original trigger, such as xerosis, eczema, bug bite, or even psoriasis.

• The chronicity of the problem, sometimes extreme (as in this case), is not only common but often diagnostic.

• Postinflammatory color changes, especially on darker skinned individuals, are common with LSC.

• Other common areas for LSC include the scrotum/vulvae and nuchal scalp.