What is Pachyonychia Congenita?
PC is an ultra rare genetic skin disorder caused by a single mutation in one of at least four keratin genes including K6a, K6b, K16 or K17. PC may be hereditary (inherited from a parent who has PC) or may be spontaneous (a mutation occuring when no parent or other family member has PC). Features of PC may include:

1 Painful blisters and calluses on hands and feet (focal palmar and plantar hyperkeratosis)

2 Thickened Nails (hypertrophic nail dystrophy or pachy-onychia)

3 Follicular hyperkeratosis (bumps around hairs at friction sites such as waist, hips, knees, elbows)

4 Leukokeratosis of the oral mucosa (white film on tongue, cheeks and sometimes larynx)

5 Cysts of various types (including steatocystoma and pilosebaceous cysts)

Other features include sores at the corner of the mouth (angular chelitis); teeth at or before birth (natal or pre-natal teeth); hoarse voice (laryngeal involvement). Note: Some with PC often suffer intense pain near the jaw or ears lasting 15-25 seconds when beginning to eat. This may be connected to salivary glands rather than to ears. More research is needed on this.