Scaly plaques includes an unrelated admixture of neoplastic and inflammatory disorders characterized by larger, usually sharply defined palpable lesions, with variable scale.
Important History Questions
How long has the lesion(s) been present?
Although all the lesions can be chronic, mycosis fungoides and psoriasis are often present for years.
Have you had a similar lesion(s) in the past?
A “yes” answer favors a disorder with a genetic basis, such as psoriasis, whereas pityriasis rubra pilaris is usually a onetime occurrence.
Do any of your immediate relatives have psoriasis?
A “yes” answer indicates a predisposition for the development of psoriasis. Rarely, pityriasis rubra pilaris can also be familial.
How are you treating your skin condition?
Many patients use home-based, over-the-counter (OTC), or prescription remedies that can alter the appearance of the condition.
Has the skin condition ever been biopsied?
This could be helpful in regard to any of the conditions in this chapter; however, it is especially important in mycosis fungoides. If this is a clinical consideration, have all previous biopsies reviewed by a pathologist or dermatopathologist with expertise in this area because the diagnosis is often missed.
Are you taking any medications?
Some medications may precipitate or aggravate some of the disorders discussed in this chapter. For example, psoriasis can be worsened by beta blockers, lithium, and terbinafine. Pityriasis rubra pilaris is also notoriously resistant to treatment with topical and systemic corticosteroids. We have seen more than one example in which this was the first clue to a diagnosis of evolving pityriasis rubra pilaris.
Have you had any recent illnesses or infections?
This is a very important question because psoriasis and reactive arthritis are genetic disorders that are often triggered by an infection. In particular, you would be interested in streptococcal infections for psoriasis and either an enteric infection or sexually acquired disease for reactive arthritis.
Important Physical Findings
What is the distribution of the lesions?
Some of the cutaneous disorders demonstrate a characteristic location. For example, psoriasis frequently affects areas that are susceptible to trauma, such as the elbows and knees, whereas mycosis fungoides often begins in the girdle area.
Is the Koebner phenomenon present?
Of the disorders with large plaques and scale, only psoriasis demonstrates lesions at the sites of minor trauma.
Is the oral mucosa involved?
Although reactive arthritis frequently has oral involvement, psoriasis only rarely involves the oral cavity, whereas pityriasis rubra pilaris and mycosis fungoides almost never present with oral lesions.
Are the nails normal or abnormal?
The nails are frequently involved in psoriasis and reactive arthritis, whereas those with mycosis fungoides and pityriasis rubra pilaris usually have normal nails.
Is there any historical or clinical evidence of arthritis?
This is an extremely important question, not only from a diagnostic standpoint but also from a therapeutic standpoint, because joint involvement is the finding that usually dictates therapy for psoriasis and reactive arthritis.
Plaque Psoriasis
ICD10 code L40.0
GENETIC DISEASE WITH A TRIGGER
- •
Beta blockers (most common)
- •
Infliximab—paradoxic effect
- •
Lithium
- •
Terbinafine
Pathogenesis
Psoriasis is a common hereditary disease with a chronic course that primarily affects the skin, with variable involvement of joints and oral mucosa. It has been estimated that up to 7 million Americans have psoriasis. Psoriasis is a genetic disorder that usually arises in adolescents and adults after a trigger, such as a streptococcal infection, recent life crisis, skin injury, drugs, and alcohol and tobacco use.
Clinical Features
- •
Psoriasis may affect any area of the body; however, there is a distinct predilection to involve areas of trauma, such as the elbows, knees, and intergluteal fold.
- •
The primary lesion in a developed disease is an erythematous papule or plaque, with white adherent scale ( Figs. 8.1–8.3 ). Scale is often absent in inverse psoriasis ( Fig. 8.4 ), where the skin is moist.
Fig. 8.1
Patient with numerous well-demarcated plaques of variable size, with focal marked scaling on the back.
(From the Fitzsimons Army Medical Center Collection, Aurora, CO.)
Fig. 8.2
Close-up view of a characteristic lesion of a patient with psoriasis, with sharply demarcated borders and marked white scale.
(From the Fitzsimons Army Medical Center Collection, Aurora, CO.)
Fig. 8.3
Psoriasis of the palms and soles may show sharply demarcated plaques, as seen here, or may have a diffuse pattern resembling that of hand dermatitis.
(From the William Weston Collection, Aurora, CO.)
Fig. 8.4
Patient with inverse psoriasis of the axillae. Psoriasis in moister intertriginous areas often lacks scale; however, in contrast to dermatitis, the lesions are usually sharply demarcated, as demonstrated here.
- •
The Koebner phenomenon occurs in about 5% of patients.
- •
Nail involvement is common but not always present; it usually consists of variable numbers of distinct nail pits. Less common nail manifestations include yellowish-brown areas of discoloration below the nail (so-called oil spots) and full-thickness nail dystrophy (see Chapter 25 ).
- •
Patients may also demonstrate pustular lesions and may actually report a history of transforming back and forth between classic papulosquamous lesions and pustular lesions.
Diagnosis
- •
The clinical presentation of a papulosquamous eruption, with a distinct edge and silvery scale, in a characteristic distribution is usually diagnostic. Psoriasis is usually not pruritic in 80% of cases.
- •
The presence of the Koebner phenomenon is strongly supportive of the diagnosis.
- •
The presence of significant nail pitting or oil spots in the nail bed is strongly suggestive of psoriasis.
- •
In regard to family history, first-degree relatives with psoriasis can be identified in about one-third of patients.
- •
Rare cases may require a 3- or 4-mm punch biopsy of a well-developed lesion (more likely diagnostic).
Treatment
The selection of therapy depends on the patient’s age and general health, cost, local availability of specialized treatment facilities, type of psoriasis (e.g., pustular vs. plaque), distribution of psoriatic lesions, extent of involvement, experience of the health care provider, and motivation of the patient.
- •
Topical options include corticosteroids of varying strength, depending on the location, severity of disease, and response to therapy. Approximately 80% of patients treated with topical corticosteroids will demonstrate significant clearance.
- •
Other commonly used topical options include calcipotriol, coal tar products, salicylic acid, tazarotene, and tacrolimus. Patients who do not respond to topical therapy should be evaluated by a dermatologist for alternative therapy.
- •
Ionizing radiation therapies include natural sunlight (cheapest option), ultraviolet B (UVB) phototherapy (to include narrow-band UVB), Goeckerman regimen (UVB + coal tar), PUVA phototherapy (methoxsalen + UVA), and 308-nm excimer laser.
- •
Systemic therapy options include methotrexate, mycophenolate, acitretin, cyclosporine, alefacept, infliximab, adalimumab, secukinumab, and etanercept.
- •
In patients with guttate psoriasis, or patients with a sudden flare of psoriasis, consider empiric oral antibiotics to eliminate infectious triggers.
- •
Discontinue any drugs implicated in triggering or aggravating psoriasis.
Plaque Psoriasis
ICD10 code L40.0
GENETIC DISEASE WITH A TRIGGER
- •
Beta blockers (most common)
- •
Infliximab—paradoxic effect
- •
Lithium
- •
Terbinafine
Pathogenesis
Psoriasis is a common hereditary disease with a chronic course that primarily affects the skin, with variable involvement of joints and oral mucosa. It has been estimated that up to 7 million Americans have psoriasis. Psoriasis is a genetic disorder that usually arises in adolescents and adults after a trigger, such as a streptococcal infection, recent life crisis, skin injury, drugs, and alcohol and tobacco use.
Clinical Features
- •
Psoriasis may affect any area of the body; however, there is a distinct predilection to involve areas of trauma, such as the elbows, knees, and intergluteal fold.
- •
The primary lesion in a developed disease is an erythematous papule or plaque, with white adherent scale ( Figs. 8.1–8.3 ). Scale is often absent in inverse psoriasis ( Fig. 8.4 ), where the skin is moist.
Fig. 8.1
Patient with numerous well-demarcated plaques of variable size, with focal marked scaling on the back.Related posts:
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