Subjective
In this scenario, the patient is a 33 years old Caucasian male with no significant prior medical or surgical history. He comes into the office with a complaint about a persistent rash on his skin. The patient claims that the symptoms first manifested approximately a week ago. When questioned about itchiness or pain, he admits that the area sometimes feels irritated, but does not significantly hurt. According to the patient, the region appears to be limited to a patch of reddened skin on his upper back. The manifestations of the increases in intensity do not seem to correlate to any pattern the man can observe. No other symptoms are present, and the patient claims to be in generally good condition, lead a healthy lifestyle, and have few to no allergies.
Objective
An examination of the problematic area reveals that there is a patch of skin of a considerably different color from the rest. The spot is reddened and roughly circular, approximately four centimeters in diameter. The area is slightly upraised and appears to have silvery discolorations scattered across its surface. The texture feels rough to the touch, and the patient can feel the contact without experiencing any particular discomfort. The spot does not feel significantly hotter than the surrounding area of the skin, and the patient’s temperature is normal. A further examination reveals no other places with similar characteristics, and the rest of the surface appears to be in good condition.
Assessment
Differential Diagnosis 1: Plaque Psoriasis
Pathophysiology
Plaque psoriasis is the most common variation of the skin condition, which is caused by immune system malfunctions. According to Menter (2016), this particular variety manifests itself as well-defined plaques of one to several centimeters in size, with thin silvery scales appearing on their surface. The condition is incurable and carries a high risk of comorbidities surfacing along with considerable negative impacts (Menter, 2016).
Pertinent Positive Findings
The description of the patient’s rash roughly matches the symptoms of the condition, particularly with regards to the specifics of the area. There are no other clinical manifestations, a trait often associated with psoriasis (Menter, 2016). Furthermore, itchiness, or pruritus, another trait of the condition, is also present.
Pertinent Negative Findings
The rash is not symmetrical, unlike what Menter (2016) asserts is the common tendency for psoriasis. Furthermore, the patient does not report any pain or malaise nor match the risk factors described by Menter (2016).
Rationale
While the patient does not match all of the specifics of psoriasis, Menter (2016) mentions that the condition can manifest in various ways that complicate diagnosis. The patient matches one of the two bimodal distribution groups of the illness, and its genetic nature means that risk factors do not necessarily have to be associated with the emergence of the condition (Menter, 2016). As such, a diagnosis of psoriasis appears to be appropriate, though testing should be conducted for other possibilities.
Differential Diagnosis 2: Atopic Dermatitis
Pathophysiology
Atopic dermatitis, also known as eczema, is a chronic relapsing illness that affects a significant portion of people worldwide. According to Sherazi et al. (2016), it is characterized by “pruritic, erythematous and scaly skin lesions” (p. 57). The condition is genetic, though various risk factors can complicate it or make it more likely (Sherazi et al., 2016).
Pertinent Positive Findings
The rash is similar to those caused by atopic dermatitis, is reddened, itchy, and scaly. The sudden quality of the lesion’s appearance also matches eczema’s tendency for sudden appearances, or flares (Sherazi et al., 2016).
Pertinent Negative Findings
Asthma is frequently associated with allergy (Sherazi et al., 2016), which the patient did not report. Furthermore, the condition usually surfaces during childhood and continues into adulthood (Sherazi et al., 2016), but the man claims he has no history of any skin conditions. Lastly, atopic dermatitis in adults tends to concentrate on the face, neck, and hands (Sherazi et al., 2016), and none of the locations match the patient’s symptoms.
Rationale
There is considerable circumstantial evidence that suggests that eczema should not be the cause of the patient’s skin irritation. However, much of it relies on unreliable information, as the patient may not remember past episodes or misreport his allergies due to factors such as lack of exposure. Ultimately, atopic dermatitis should not be considered the most likely diagnosis, but it deserves investigation.
Differential Diagnosis 3: Tinea Versicolor
Pathophysiology
Tinea versicolor is a condition caused by a variety of yeast that enters a state of uncontrolled growth and produces a pigmentation of the skin. According to Gantz & Allen (2016), the condition often manifests on the upper trunk and takes on a chronic nature. Like the other two conditions, it may be affected by a genetic predisposition that pushes a part of normal skin flora to proliferate (Gantz & Allen, 2016).
Pertinent Positive Findings
The location of the reddened patch, its color, and its scaly nature all conform to the symptoms of tinea versicolor as presented by Gantz & Allen (2016). Furthermore, the yeast responsible for the condition produces agents that reduce inflammation (Gantz & Allen, 2016), which is consistent with the evaluation of the patch.
Pertinent Negative Findings
Gantz & Allen (2016) mention that tinea versicolor tends to produce no pruritus and generally be asymptomatic. Furthermore, the symptoms do not include the silvery discolorations discovered during the examination.
Rationale
It is unlikely that tinea versicolor is responsible for the patient’s rash due to a mismatch in the symptoms. The basic facts are similar, but some of the particulars reported by the patient should not usually be presented during a case of the illness. Nevertheless, an investigation is warranted, mainly as this condition is easier to identify than others due to its microbial nature. According to Gantz & Allen (2016), skin scrapings can be analyzed for the presence of spores, conclusively confirming or denying the yeast infection hypothesis.
Plan
Skin Scraping Analysis
Rationale: An analysis of skin scrapings for yeast spores can confirm or rule out the tinea versicolor diagnosis. It is also possible to perform a biopsy to help evaluate whether eczema or psoriasis is the correct diagnosis (Salvador, Romero-Perez, & Encabo-Durán, 2017).
IgE Blood Test
Rationale: According to Salvador et al. (2017), the determination of the patient’s IgE serum levels is among the first actions that should be taken when suspecting atopic dermatitis. The test can help reinforce the diagnosis or debunk it based on the concentration discovered.
Skin Allergy Testing
Rationale: According to Gantz & Allen (2016), atopic dermatitis is associated with manifestations of allergy. Discovery of a reaction to an agent would reinforce the hypothesis that eczema is the correct diagnosis.
The Koo-Menter Psoriasis Instrument
Rationale: Psoriasis often has a considerable impact on the patient’s well-being due to its pronounced manifestations. According to van Voorhees, Feldman, Lebwohl, Mandelin, and Ritchlin (n.d.), the tool is effective for the assessment of various factors about the patient’s quality of life and the severity of the condition.
Tuberculosis Testing
Rationale: Many treatment options proposed for psoriasis by van Voorhees et al. (n.d.) propose that the physician should test for tuberculosis at baseline and annually. The use of biologics options can exacerbate the bacterial disease if used without proper consideration.
References
Gantz, M., & Allen, H. B. (2016). Psoriasis, atopic dermatitis, Lyme disease, and tinea versicolor: All caused by microbes but none a classic infection. Journal of Clinical & Experimental Dermatology Research, 7(4). Web.
Menter, A. (2016). Psoriasis and psoriatic arthritis overview. The American Journal of Managed Care, 22(8), 216-224.
Salvador, J. F. S., Romero-Pérez, D., & Encabo-Durán, B. (2017). Atopic dermatitis in adults: a diagnostic challenge. Journal of Investigative Allergology and Clinical Immunology, 27(2), 78-88.
Sherazi, B. A., Hashmi, K., Afzal, F., Hassan, S. M., Hassan, S. K., & Iqbal, M. (2016). Assessment of causes, symptoms, prevention and clinical management of pediatric atopic dermatitis. Current Science Perspectives, 2(3), 57-60.
van Voorhees, A. S., Feldman, S. R., Lebwohl, M. G., Mandelin, A., & Ritchlin, C. (n.d.) The psoriasis and psoriatic arthritis pocket guide (5th ed.). Web.