Summary of a Patient’s History
Narrowing the Differential Diagnosis
- Chronic Urticaria
- Pityriasis Rosea
- Contact Dermatitis
Analyzing the Differential Diagnoses
Among the identified differential diagnoses, chronic urticaria is the most probable one. Urticaria, also called hives, is a frequent dermatologic disorder, which is characterized by pink, itchy wheals that can appear all over the body and vary in size from some millimeters to centimeters. Acute form lasts up to six weeks and is less prevalent. Therefore, the patient in the case under analysis is likely to have a chronic form, which persists for more than six weeks (Weller, Hunter, & Mann, 2015). Also, the location of skin symptoms on the trunk as well as upper and lower extremities is a characteristic of urticaria. The triggers of the patient’s condition are not known, which is typical of chronic urticaria.
Contact dermatitis, which is also a common skin disorder, is less probable in this case. It is usually caused by a trigger that touches the skin and causes a red rash. Consequently, this diagnosis is less applicable to the patient under consideration since the manifestations he observes are pale red. Moreover, the patient experiences bumpy wheals, which is not typical of contact dermatitis. Also, contact dermatitis usually has a definite trigger for the reaction, such as an ingredient in makeup, metal in jewelry, or a certain detergent. Another difference is that patients with hives usually complain of an itchy reaction, while individuals with contact dermatitis experience a stinging or burning feeling on the skin. Finally, the skin reaction is localized on the areas of contact with a trigger.
The third differential, pityriasis rosea, is the least probable of diagnoses for the patient under consideration. Although pityriasis rosea is also a common skin disease, it has a different clinical picture. Thus, a typical variant of pityriasis rosea progress is the development of a ‘herald’ or ‘mother’ plague, which is bigger than the others that appear later (Weller et al., 2015). Moreover, unlike chronic urticaria, pityriasis rosea is likely to disappear without treatment.
Probing the Selected Diagnosis
To prove the selected diagnosis, some knowledge gaps should be bridged, which can be achieved by asking additional questions.
- How can the triggers of chronic urticaria be identified in case a patient is not aware of them?
- What are the additional opportunities for improving the patient’s condition in addition to the prescribed treatment?
- Which factors apart from the rash duration, location, and color are significant for selecting among the differentials?
Plan
- Review the possible endogenous causes of urticaria (viral, bacterial, or mycoplasma infection; intestinal parasites, cancer, etc.) (Weller et al., 2015).
- Review exogenous causes of urticaria (drugs, foods, bites, inhalants, etc.) (Weller et al., 2015).
- Attention to patient’s history and precision in the chronology of symptoms.
- Clinical tests, such as complete blood count.
- Selection of medication:
- Prescription of second-generation H1 antihistamine
- In case of no effect, addition of different second-generation H1 antihistamine or H2 antihistamine or leukotriene receptor antagonist
- If there is no sufficient effect, the high-potency antihistamine is added (Schaefer, 2017).
- Application of calamine lotion and OTC Benadryl capsule
- Warm or cold shower to reduce itching sensations.
Self-Directed Learning
While patient history is more important for diagnosing skin diseases than laboratory tests, they also have a meaningful role. For example, a complete blood count or urine test can be used to support a diagnosis. Thus, I will investigate the issue of laboratory test utilization for diagnosing skin disorders.
References
Schaefer, P. (2017). Acute and chronic urticaria: Evaluation and treatment. American Family Physician, 95(11), 717-724.
Weller, R., Hunter, H., & Mann, M. (2015). Clinical dermatology (5th ed.). Hoboken, NJ: Willey Blackwell.