Differential Diagnosis for Pruritic Rash on the Inguinal Region and Vulva
- Single Most Likely Diagnosis
- Candidiasis: Given the patient's symptoms of a pruritic rash in the inguinal and vulvar area, particularly after wearing tight clothing, and her recent use of systemic corticosteroids which can predispose to fungal infections, candidiasis is a highly plausible diagnosis. The patient's obesity (BMI 32 kg/m2) and potential for increased moisture in the inguinal and vulvar area also support this diagnosis.
- Other Likely Diagnoses
- Contact Dermatitis: The irritation and pruritus, especially after wearing tight clothing, could suggest contact dermatitis, either irritant or allergic. The lack of improvement with moisturizing cream does not rule out this diagnosis, as specific treatments like topical corticosteroids or avoidance of the offending agent might be necessary.
- Lichen Sclerosus: Although less common, lichen sclerosus can cause pruritic lesions in the vulvar area. The patient's history of dysplasia and subsequent cervical conization might not be directly related, but any condition affecting the genital area warrants consideration of lichen sclerosus, especially given the pruritus.
- Psoriasis or Seborrheic Dermatitis: These conditions can cause pruritic rashes and might involve the inguinal area. The patient's recent asthma exacerbation and treatment do not directly link to these conditions, but they are common enough to be considered in the differential diagnosis.
- Do Not Miss Diagnoses
- Malignancy (e.g., Vulvar Cancer): Although the patient has a history of normal Pap tests after a cervical conization for dysplasia, any new or persistent vulvar lesion, especially in a postmenopausal woman (last menstrual period 8 months ago), necessitates consideration of malignancy. Vulvar cancer can present with pruritus and skin changes.
- Invasive Fungal Infections: In immunocompromised patients or those on systemic corticosteroids, invasive fungal infections can occur. While less likely, these conditions are serious and require prompt diagnosis and treatment.
- Herpes Simplex Virus (HSV) Infection: Given the patient's new sexual partner, HSV should be considered, especially if the rash is vesicular. HSV can cause significant discomfort and requires antiviral treatment.
- Rare Diagnoses
- Lichen Planus: This is an autoimmune condition that can affect the skin and mucous membranes, including the vulva, causing pruritic lesions. It is less common than other conditions listed but should be considered if other diagnoses are ruled out.
- Zinc Deficiency: Although rare, zinc deficiency can cause skin lesions and might be considered if the patient has a poor diet or specific gastrointestinal conditions leading to malabsorption.