Hypertrophic cardiomyopathy is a genetically transmittable disease.

True. Hypertrophic cardiomyopathy (HCM) is inherited as an autosomal dominant trait and is caused by missense mutations involving a single amino acid substitution on one of several sacromeric genes. This results in disarray of cell to cell arrangement, disorganization of cellular architecture and fibrosis. Due to its variable phenotypic and clinical expression, the natural history of HCM is very unpredictable.

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Recurrent syncope is a risk factor for sudden death.

True. The usually accepted risk factors for sudden death include: previous cardiac arrest, sustained ventricular tachycardia, adverse genotype (i. B-myosin heavy chain ii. Cardiac troponin T), family history of sudden death, non-sustained ventricular tachycardia during ambulatory monitoring, recurrent syncope, abnormal decrease in exercise blood pressure and massive left ventricular wall thickness (>35mm). Implantation of an ICD should be considered for patients at high risk of sudden cardiac death, which is usually due to ventricular arrhythmia.

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Echocardiography is the diagnostic investigation.

True. Echocardiography is the investigation of choice. The M-mode and two-dimensional features of HCM on echocardiography are characteristic and echocardiography can clearly demonstrate the hypertrophic parts. Outflow tract obstruction and recognition of valvular abnormalities can also be documented. Serial echocardiography examination may also provide continuous monitoring of the progress of left ventricular function and outflow tract obstruction.

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Beta blockers are first-line therapy.

True. Beta blockers are first-line therapy for HCM regardless of the presence of left ventricular outflow obstruction. They are effective in relieving chest pain, dyspnea and syncope. For those intolerant of beta-blockers or have failed treatment, calcium channel blockers are also effective. However, these drugs do not alter the natural progression of the disease in individual patients. For non-obstructive HCM with progressive left ventricular failure, heart transplantation may be the only final resort. For those with obstruction, dual chamber pacing, alcohol septal ablation and septal myotomyectomy have been advocated with variable success. As mentioned earlier, ICD is indicated in patients with high risk for sudden arrhythmic death.

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What is the clinical diagnosis?

The clinical diagnosis is lichen striatus. It is an uncommon, self-limiting dermatosis of unknown origin. There are linear lesions consisting of small pink, red, or flesh-coloured lichenoid papules joining together to form linear bands. There is usually single, unilateral lesion which commonly involves lower or upper extremity. The lesions follow the Lines of Blaschko. It mainly affects children and is usually asymptomatic. It is non-contagious.

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What are the clinical differential diagnoses?

Clinical differential diagnoses include other dermatoses with linear distribution such as epidermal naevus. Lichen planus and psoriasis may have linear distribution, especially after trauma (isomorphic phenomenon) and may be confused with lichen striatus, but skin lesions will be more widespread.

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What are the etiology or predisposing factors?

The cause is unknown. Predisposing factors suggested include viral infection, atopy and genetic predisposition.

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How would you confirm the diagnosis?

The clinical features of lichen striatus with sudden onset of a linear eruption in a young child is very characteristic and seldom causes confusion. Skin biopsy may be required to confirm the diagnosis occasionally.

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What are the treatments?

Because the lesions usually resolve within one year, reassurance is usually all that required. Emollients and topical steroids may be used for symptom relief. Post-inflammatory hypopigmentation may occur after disease resolution.

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