Mother Knows Best

About six months ago, an 8-year-old girl developed an asymptomatic rash near her ear. Her mother suspects it is psoriasis, which runs heavily in the family—but their primary care provider favors a fungal diagnosis. He prescribes a succession of topical and oral antifungal medications (including nystatin and terbinafine), which yield no discernable improvement. At this point, referral to dermatology is made.  

The child’s mother denies any history of recent infections (eg, strep throat) on her daughter’s behalf. Furthermore, there are no reports of pain associated with the rash or elsewhere.

EXAMINATION
The rash, which is confined to the external right ear, is composed of uniformly smooth white scale on a faintly salmon base. The entire lesion measures about 3 cm at its widest point, and the margins are arciform and well-defined.

No such lesions are seen elsewhere, but tiny pits can be seen on one fingernail.

What is the diagnosis?

In psoriasis, keratinocytes matriculate upward from the basal layer to the skin surface at four times the normal rate—so quickly that they have no chance to lose their nuclei (as they normally would). They then pile up, creating plaques of micaceous white scale on a salmon-pink base. Histologically, the smoothly undulating dermoepidermal junction is jammed together, producing fused ridges with clumps of neutrophils on their tips.

While it favors extensor surfaces of extremities, psoriasis can show up anywhere on the body—on the genitals, mouth, and in the nails, where it can cause pits, dystrophy, discoloration, onycholysis, and onychorrhexis.

Unfortunately, this is probably just the beginning of this child’s psoriasis. The good news is that we’re in a golden age of psoriasis treatment, with more drugs than ever to choose from and even more in development. For this patient, we used a keratolytic agent (urea lotion) to thin out the surface scale, in order to allow a class 4 steroid cream to reach the pink inflammatory portion. Within a month, most of this patch had cleared, though we can be fairly sure it and others like it will be back. Education and ongoing follow-up will be needed, in case she is among the 20% to 25% of patients who will develop psoriatic arthropathy, a crippling form of arthritis.

It is certainly possible to develop a fungal infection on or in an ear, but for that to happen, there has to be a source (eg, animal, person, soil). Moreover, the scale would look entirely different, with clearing centers and advancing margins. The likely truth is that this was called “fungal” for lack of any other suspects.

TAKE-HOME LEARNING POINTS

• White scale on a salmon-pink base typifies psoriasis vulgaris, a very common diagnosis that is often mistaken for fungal infection; biopsy can be extremely helpful in establishing or ruling out this diagnosis.
• Psoriasis has a genetic basis, with many gene loci identified to date, but only about 30% of affected patients can attest to a family history.
• In addition to having unsightly, often itchy lesions, psoriasis patients are also at risk for psoriatic arthropathy, a potentially crippling condition.
• The best news is that we have many drugs with which to treat this disease, including a whole family of drugs termed “the biologics,” which directly (and successfully!) address the disease.

About six months ago, an 8-year-old girl developed an asymptomatic rash near her ear. Her mother suspects it is psoriasis, which runs heavily in the family—but their primary care provider favors a fungal diagnosis. He prescribes a succession of topical and oral antifungal medications (including nystatin and terbinafine), which yield no discernable improvement. At this point, referral to dermatology is made.  

The child’s mother denies any history of recent infections (eg, strep throat) on her daughter’s behalf. Furthermore, there are no reports of pain associated with the rash or elsewhere.

EXAMINATION
The rash, which is confined to the external right ear, is composed of uniformly smooth white scale on a faintly salmon base. The entire lesion measures about 3 cm at its widest point, and the margins are arciform and well-defined.

No such lesions are seen elsewhere, but tiny pits can be seen on one fingernail.

What is the diagnosis?

In psoriasis, keratinocytes matriculate upward from the basal layer to the skin surface at four times the normal rate—so quickly that they have no chance to lose their nuclei (as they normally would). They then pile up, creating plaques of micaceous white scale on a salmon-pink base. Histologically, the smoothly undulating dermoepidermal junction is jammed together, producing fused ridges with clumps of neutrophils on their tips.

While it favors extensor surfaces of extremities, psoriasis can show up anywhere on the body—on the genitals, mouth, and in the nails, where it can cause pits, dystrophy, discoloration, onycholysis, and onychorrhexis.

Unfortunately, this is probably just the beginning of this child’s psoriasis. The good news is that we’re in a golden age of psoriasis treatment, with more drugs than ever to choose from and even more in development. For this patient, we used a keratolytic agent (urea lotion) to thin out the surface scale, in order to allow a class 4 steroid cream to reach the pink inflammatory portion. Within a month, most of this patch had cleared, though we can be fairly sure it and others like it will be back. Education and ongoing follow-up will be needed, in case she is among the 20% to 25% of patients who will develop psoriatic arthropathy, a crippling form of arthritis.

It is certainly possible to develop a fungal infection on or in an ear, but for that to happen, there has to be a source (eg, animal, person, soil). Moreover, the scale would look entirely different, with clearing centers and advancing margins. The likely truth is that this was called “fungal” for lack of any other suspects.

TAKE-HOME LEARNING POINTS

• White scale on a salmon-pink base typifies psoriasis vulgaris, a very common diagnosis that is often mistaken for fungal infection; biopsy can be extremely helpful in establishing or ruling out this diagnosis.
• Psoriasis has a genetic basis, with many gene loci identified to date, but only about 30% of affected patients can attest to a family history.
• In addition to having unsightly, often itchy lesions, psoriasis patients are also at risk for psoriatic arthropathy, a potentially crippling condition.
• The best news is that we have many drugs with which to treat this disease, including a whole family of drugs termed “the biologics,” which directly (and successfully!) address the disease.

About six months ago, an 8-year-old girl developed an asymptomatic rash near her ear. Her mother suspects it is psoriasis, which runs heavily in the family—but their primary care provider favors a fungal diagnosis. He prescribes a succession of topical and oral antifungal medications (including nystatin and terbinafine), which yield no discernable improvement. At this point, referral to dermatology is made.  

The child’s mother denies any history of recent infections (eg, strep throat) on her daughter’s behalf. Furthermore, there are no reports of pain associated with the rash or elsewhere.

EXAMINATION
The rash, which is confined to the external right ear, is composed of uniformly smooth white scale on a faintly salmon base. The entire lesion measures about 3 cm at its widest point, and the margins are arciform and well-defined.

No such lesions are seen elsewhere, but tiny pits can be seen on one fingernail.

What is the diagnosis?

In psoriasis, keratinocytes matriculate upward from the basal layer to the skin surface at four times the normal rate—so quickly that they have no chance to lose their nuclei (as they normally would). They then pile up, creating plaques of micaceous white scale on a salmon-pink base. Histologically, the smoothly undulating dermoepidermal junction is jammed together, producing fused ridges with clumps of neutrophils on their tips.

While it favors extensor surfaces of extremities, psoriasis can show up anywhere on the body—on the genitals, mouth, and in the nails, where it can cause pits, dystrophy, discoloration, onycholysis, and onychorrhexis.

Unfortunately, this is probably just the beginning of this child’s psoriasis. The good news is that we’re in a golden age of psoriasis treatment, with more drugs than ever to choose from and even more in development. For this patient, we used a keratolytic agent (urea lotion) to thin out the surface scale, in order to allow a class 4 steroid cream to reach the pink inflammatory portion. Within a month, most of this patch had cleared, though we can be fairly sure it and others like it will be back. Education and ongoing follow-up will be needed, in case she is among the 20% to 25% of patients who will develop psoriatic arthropathy, a crippling form of arthritis.

It is certainly possible to develop a fungal infection on or in an ear, but for that to happen, there has to be a source (eg, animal, person, soil). Moreover, the scale would look entirely different, with clearing centers and advancing margins. The likely truth is that this was called “fungal” for lack of any other suspects.

TAKE-HOME LEARNING POINTS

• White scale on a salmon-pink base typifies psoriasis vulgaris, a very common diagnosis that is often mistaken for fungal infection; biopsy can be extremely helpful in establishing or ruling out this diagnosis.
• Psoriasis has a genetic basis, with many gene loci identified to date, but only about 30% of affected patients can attest to a family history.
• In addition to having unsightly, often itchy lesions, psoriasis patients are also at risk for psoriatic arthropathy, a potentially crippling condition.
• The best news is that we have many drugs with which to treat this disease, including a whole family of drugs termed “the biologics,” which directly (and successfully!) address the disease.