先天性无痛无汗症

先天性无痛无汗症(Congenital insensitivity to pain with anhidrosis，CIP)又称为遗传性感觉和自主神经障碍(HSAN)Ⅳ型，一种罕见的常染色体隐性遗传病
主要临床表现为：
(1)无痛：痛觉缺失多为全身性，80％的患者痛觉完全丧失，触觉良好，常发生自残行为及烧伤、烫伤，走路跛行或骨折后无疼痛感。

(2)无汗、发热：全身皮肤干燥，无汗，手足部皮肤粗糙、皲裂，个别患者夏季仅鼻翼两侧或后背有汗；因为排汗功能障碍患者生后即有反复高热，表现为弛张热或不规则热。

输抗生素或肌注退热药无效，物理降温有效。

约20％患儿3岁时因高热死亡。

本病的主要诊断依据是碘淀粉法发汗定性试验，皮肤活检可确诊。

(3)关节囊松弛、骨折：全身关节囊松弛，各关节活动度超出正常范围，常发生关节脱位，浅表关节囊肿胀。

因缺乏疼痛防卫反射，常发生骨折。

须与因父母虐待导致的儿童反射性骨折相鉴别。

(4)智力迟缓：身材矮小，精神运动发育落后，韦克斯勒成人智力诊断测验法测定大多为中度智力缺陷。

本病无特殊治疗方法，对高热可采用物理降温，防止体温过高或惊厥，防止自残和外伤。

我国有报道两例无痛无汗症的孩子，与上述叙述有出入，两个孩子智力基本正常，而且虽然家中三个孩子有一个正常但三个孩子及其父母的染色体核型均无异常，家族中无其他患者，只能初步猜测是基因突变。

其他症状均符合无痛无汗症的表现。

另外先天性无痛无汗症还要与Riley-Day 综合征和Lesh-Nyhan综合征鉴别：
Riley-Day 综合征也是常隐遗传病主要临床表现为
Poor growth ，Feeding difficulties ，Breath holding ，Sweating while eating ，L ong episodes of vomiting ，Lack of response to painful stimuli ，Seizures ，Hyp otonia, low muscle tone ，Repeated fevers ，Repeated episodes of high blood pre ssure ，poor coordination - unsteady gait ，Unusually smooth tongue surface ，D ecreased taste ，Diarrhea ，Constipation ，Severe scoliosis ，Skin blotching 。

Lesh-Nyhan综合征是X连锁隐性遗传，主要临床表现是：
At birth, males with Lesch-Nyhan syndrome appear completely normal. Development is usually normal for the first few months. Symptoms develop between three to six months of age. Sand-like crystals of uric acid in the diapers may be one of the first symptoms of the disease. The baby may be unusually irritable. Typica lly, the first sign of nervous system impairment is the inability to lift their head or sit up at an appropriate age. Many patients with Lesch-Nyhan will neve r learn to walk. By the end of the first year, writhing motions (athetosis), an d spasmodic movements of the limbs and facial muscles (chorea) are clear eviden ce of defective motor development.
The compulsive self-injury associated with Lesch-Nyhan syndrome begins, on aver age, at three years. The self-injury begins with biting of the lips and tongue.
As the disease progresses, affected individuals frequently develop finger biti ng and head banging. The self-injury can increase during times of stress. Males with Lesch-Nyhan disease may also develop kidney damage due to kidney sto nes. Swollen and tender joints (gout) is another common problem.。