Diagnosis: Prurigo nodularis
An elderly man presents with multiple hyperkeratotic itchy nodules on his forearms, persisting for several months. The lesions are characterized by intense itching and have significantly impacted his quality of life. This case highlights the clinical features and management strategies for a common but often underdiagnosed condition.
An 80-year-old male presents with a 6-month history of multiple, intensely itchy nodules on his forearms. The patient reports that the itching is worse at night, leading to scratching and secondary excoriations. On examination, multiple hyperkeratotic nodules are noted, measuring 1-2 cm in diameter, with a thickened crust on the surface. There is no evidence of underlying dermatosis or systemic symptoms.Location: Predominantly on the forearms and extensor surfaces.Lesion characteristics: Firm, dome-shaped, and hyperkeratotic.Itch severity: Significant, often leading to secondary excoriations.Distribution: Symmetrical, with no signs of inflammation or infection.Additional findings: No associated lymphadenopathy or systemic symptoms.
The patient reports the onset of lesions approximately 6 months ago, initially as small itchy bumps that gradually increased in size. He identifies a history of chronic pruritus and a tendency to scratch the lesions, which worsened with stress and colder weather. Prior treatments included topical corticosteroids and antihistamines, which provided minimal relief. His past medical history includes hypertension and osteoarthritis. He lives alone, has no known drug allergies, and denies any recent travel or exposure to new medications.Onset: Lesions began approximately 6 months ago.Triggers: Stress and colder weather exacerbate itching.Prior treatments: Topical corticosteroids and antihistamines with minimal improvement.Medical history: Hypertension and osteoarthritis.Social history: Lives alone, no known drug allergies.Exposure history: No recent travel or exposure to new medications.
Acute / First-Line ManagementTopical corticosteroids: High-potency steroid ointments (e.g., clobetasol propionate 0.05% applied twice daily) can help reduce inflammation and itching.Antihistamines: Oral antihistamines (e.g., cetirizine 10 mg daily) may alleviate pruritus, especially at night.Emollients: Regular use of emollients can help maintain skin hydration and barrier function.Workup and Diagnostic ConfirmationClinical diagnosis: The diagnosis is primarily clinical based on characteristic lesions and history.Skin biopsy: Considered if the diagnosis is uncertain or if there is concern for an alternative condition.Laboratory tests: May be warranted to rule out underlying systemic conditions if indicated.Long-Term ManagementBehavioral modification: Education on avoiding scratching and triggers is crucial for long-term management.Phototherapy: Ultraviolet light therapy (e.g., narrowband UVB) may be beneficial for recalcitrant cases.Systemic therapies: In refractory cases, consider systemic therapies such as methotrexate or dupilumab.
Chronic eczema: Often presents with pruritic, excoriated lesions, but typically has an inflammatory component and may involve flexural areas.Psoriasis: Characterized by well-defined plaques with silvery scales, often on extensor surfaces, and may have a family history.Follicular keratosis: Presents as small, rough papules, often on the upper arms and thighs, but lacks the intense pruritus.Keratoacanthoma: Rapidly growing nodules with a central keratin plug, typically solitary and may require biopsy for diagnosis.Basal cell carcinoma: Can present as nodular lesions, particularly in sun-exposed areas, but usually lacks significant itching.Scabies: Pruritic papules, often with burrows, typically in intertriginous areas, and associated with a close contact history.Pruritic papular eruption: Common in patients with HIV or other immunocompromised states, presenting as pruritic papules often on the trunk.Granuloma annulare: Presents with annular plaques, often asymptomatic, and typically resolves spontaneously.
High-Yield PearlsDiagnosis: Prurigo nodularis is often underrecognized; a thorough history and examination are essential for diagnosis.Triggers: Identifying and managing triggers, such as stress or environmental factors, is crucial for effective treatment.Topical therapy: High-potency topical corticosteroids are first-line for reducing inflammation and pruritus.Phototherapy: Narrowband UVB can be an effective treatment option for chronic cases resistant to topical therapies.Systemic options: In recalcitrant cases, consider systemic therapies like methotrexate or biologics.Effective management of prurigo nodularis hinges on understanding the interplay between chronic itch and skin barrier dysfunction.
Tags: prurigo nodularis, common