Hyperkeratosis as a clue to diagnosis in a patient with myopathy.

Muscle involvement in several forms can be the first manifestation of untreated hypothyroidism.[1] Although 75% of patients with acquired hypothyroidism have muscle complaints such as weakness, cramps, and myalgias; muscle hypertrophy is an extremely rare finding.[2] This condition is named as Hoffmann's syndrome and is usually reported in young adults.[34] Here, we report distinctive hyperkeratosis and muscle hypertrophy in an adolescent secondary to untreated autoimmune hypothyroidism.

A 12-year 1-month-old male patient admitted with fatigue, dry skin, muscle pain, and short stature. His height was 136.5 cm (−2.01 standard deviation score (SDS)) and weight was 35.1 kg (−1.14 SDS). His pulse rate was slow (55 beats per min) and blood pressure was normal (80/50 mmHg). The patient had a Herculean look, dry skin, and hyperkeratosis over extensor surfaces of the joints [Figures 1 and 2]. He had marked hypertrophy in shoulder and calf muscles bilaterally [Figure 3]. On palpation these muscles were stiff. Physical examination revealed proximal muscle weakness (Medical Research Council Scale: 4/5) and diminished deep tendon reflexes. Creatine phosphokinase value was 1,850 U/L (normal (N): 30-200). Electromyography was found normal. His laboratory measurements revealed elevated thyrotropin and low free thyroxine levels with positive antithyroid antibodies. Genetic analysis for dystropin gene revealed no mutation.

Figure 1

Bilateral hyperkeratosis at patellar area

Figure 2

Lichenification of the skin

Figure 3

Muscle hypertrophy of calf

Hoffmann's syndrome is a rare but treatable form of acquired myopathies and can be seen in children due to untreated hypothyroidism. Muscle hypertrophy accompanied by hyperkeratosis and short stature should alert clinicians for possible hormonal etiology.